当心空指针异常——将头像存储到T_User用户信息表里

概述写在前面的话：     找工作已经告一段落，整天无所事事找不到目标的日子也被涪陵之行治愈，现在的我只剩下满满的正能量！吼吼，俺要努力做课题，为毕设做准备啦！一想到明年就能自食其力了就开心，钱钱啊~嘿嘿~     暑假的时候，为了找工作能更好地演示我的APP，特意对软件进行了代码调整，也就是只能看，不能用（不能实现检测的功能呢），于是乎，俺重拾课题的第一步自然就必须得把APP的代码改过来，还我娃本来

写在前面的话：

找工作已经告一段落，整天无所事事找不到目标的日子也被涪陵之行治愈，现在的我只剩下满满的正能量！吼吼，俺要努力做课题，为毕设做准备啦！一想到明年就能自食其力了就开心，钱钱啊~嘿嘿~

暑假的时候，为了找工作能更好地演示我的APP，特意对软件进行了代码调整，也就是只能看，不能用（不能实现检测的功能呢），于是乎，俺重拾课题的第一步自然就必须得把APP的代码改过来，还我娃本来面貌，哈哈！

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【功能】将头像统一存储到T_User表里，并能查询显示在界面

1.旧功能陈述

因为App是分阶段开发的，很久很久以前还没有统一创建sqlite数据库，基本是需要用到什么表和字段就现创建，后来一想不行啊，于是就本着程序员对规范代码的追求开始设计整个APP系统的数据库和表。But，由于当时时间紧，任务重，俺只得让“头像”这块儿较复杂的数据还是存在原始时代创建的数据表里，那么：

存储头像图片就用了下面这句代码：

insert(headimg(bitmap));//将头像存储到本地sqlite数据库

其中，将Bitmap格式的图片转换为byte[]类型，然后存入sqlite数据库（blob类型）时的代码如下：

/**功能模块：将头像图片存储在本地数据库 * 时间：2016.01.06 * 作者：黄永红*/ /*-将图片转化为 byte[]---------------------------------------------------------------------------------------------*/ public byte[] headimg(Bitmap bm){ ByteArrayOutputStream baos = new ByteArrayOutputStream(); bm.compress(Bitmap.CompressFormat.PNG,100,baos); return baos.toByteArray(); }public long insert(byte[] img){ //databaseHelper dbhelper =new databaseHelper(UserDetailinformation01Activity.this,"Userinformation",null,2); databaseHelper dbhelper =new databaseHelper(UserDetailinformation01Activity.this,"My_UserInfo",2); sqliteDatabase db = dbhelper.getWritableDatabase(); // sqliteDatabase db = databaseHelper.getInstance(UserDetailinformation01Activity.this).getWritableDatabase(); ContentValues values =new ContentValues(); values.put("headImage",img); //把最新设置的头像值插入表中一行 long result = db.insert("My_UserInfo",values); savetouxiang=true; db.close(); return result;}

此时，在DIalogFragment查询数据库中的头像数据，然后设置到界面上的代码如下：

//---------------------------- /*功能模块：从本地数据库里查头像并设置在界面上*/ public Bitmap getBitmap(){ databaseHelper databaseHelper=new databaseHelper(getActivity(),2); sqliteDatabase database=databaseHelper.getReadableDatabase(); Cursor cursor=database.rawquery("select * from My_UserInfo",null); //Cursor cursor=database.query("Userinformation",new String[]{"ID","phone","headImage"},"ID>=?",new String[]{"1"},null); /* while (cursor.movetoNext()){ in = cursor.getBlob(cursor.getColumnIndex("headImage")); }*/ System.out.println("头像数据库是空的额1"); if (cursor==null){ System.out.println("头像数据库是空的额"); return null; } if (cursor.movetoLast()){ in = cursor.getBlob(cursor.getColumnIndex("headImage")); System.out.println("头像数据库是空的额2"); } bmpout = BitmapFactory.decodeByteArray(in,in.length); System.out.println("查到的图片为" + bmpout); cursor.close(); database.close(); return bmpout; }

这样做的缺点是：所有的数据库表都统一了，唯独这个表 My_UserInfo 无法跟注册用户信息关联在一起。这是要出问题的哇！

2.新功能实现

整改后的数据存储都是借助数据库工具类，对封装类对象的存储。

例如对User用户数据的存储是基于UserInfo这个对象类，里面包含了姓名、电话号码、密码、头像等字段。具体代码如下：

public class UserInfo implements Parcelable{ private String IDCard; private Date activatedDate; private Date createDate; private String email; private String password; private String username; private Integer ID = null; private String phone = null; private String ActivateCode = null; private boolean isActivated = false; //----------------------------------- //健康档案里添加的一些用户信息 private String sex=null; private String birthday=null; private String height=null; private String weight=null; private String waistline=null; private Bitmap headImage=null; private String nickname=null; private int age=0; public UserInfo() { } public UserInfo(Integer ID,String phone,String username,String password,String IDCard,String email,String activateCode,boolean isActivated,Date createDate,Date activatedDate,String sex,String birthday,String height,String weight,String waistline,Bitmap headImage,String nickname,int age) { this.ID = ID; this.phone = phone; this.username = username; this.password = password; IDCard = IDCard; this.email = email; ActivateCode = activateCode; this.isActivated = isActivated; this.createDate = createDate; this.activatedDate = activatedDate; //-------------------------------------- this.sex=sex; this.birthday=birthday; this.height=height; this.weight=weight; this.waistline=waistline; this.headImage=headImage; this.nickname=nickname; this.age = age; } public Integer getID() { return ID; } public voID setID(Integer ID) { this.ID = ID; } public String getPhone() { return phone; } public voID setPhone(String phone) { this.phone = phone; } public String getUsername() { return username; } public voID setUsername(String username) { this.username = username; } public String getpassword() { return password; } public voID setPassword(String password) { this.password = password; } public voID setIDCard(String IDCard) { IDCard = IDCard; } public String getIDCard() { return IDCard; } public voID setEmail(String email) { this.email = email; } public String getEmail() { return email; } public voID setActivateCode(String activateCode) { ActivateCode = activateCode; } public String getActivateCode() { return ActivateCode; } public boolean isActivated() { return isActivated; } public voID setActivated(boolean isActivated) { this.isActivated = isActivated; } public Date getCreateDate() { return createDate; } public voID setCreateDate(Date createDate) { this.createDate = createDate; } public Date getActivatedDate() { return activatedDate; } public voID setActivatedDate(Date activatedDate) { this.activatedDate = activatedDate; } //------------------------------------------------ //健康档案里添加的用户信息 public voID setSex(String sex) { this.sex = sex; } public String getSex() { return sex; } public voID setBirthday(String birthday) { this.birthday = birthday; } public String getBirthday() { return birthday; } public voID setHeight(String height) { this.height = height; } public String getHeight() { return height; } public voID setWeight(String weight) { this.weight = weight; } public String getWeight() { return weight; } public voID setWaistline(String waistline) { this.waistline = waistline; } public String getWaistline() { return waistline; } public voID setNickname(String nickname) { this.nickname = nickname; } public String getNickname() { return nickname; } public voID setheadImage(Bitmap headImage){ this.headImage=headImage; } public Bitmap getheadImage(){ return headImage; } public int getAge() { return age; } public voID setAge(int age) { this.age = age; } public static final Parcelable.Creator<userinfo> CREATOR = new Parcelable.Creator() { public UserInfo createFromParcel(Parcel in) { UserInfo user = new UserInfo(); user.setID((Integer) in.readSerializable()); user.setPhone(in.readString()); user.setUsername(in.readString()); user.setPassword(in.readString()); user.setIDCard(in.readString()); user.setEmail(in.readString()); user.setActivateCode(in.readString()); user.setActivated(Boolean.parseBoolean(in.readString())); user.setCreateDate((Date) in.readSerializable()); user.setActivatedDate((Date) in.readSerializable()); //-------------------------------- user.setSex(in.readString()); user.setBirthday(in.readString()); user.setHeight(in.readString()); user.setWeight(in.readString()); user.setWaistline(in.readString()); user.setNickname(in.readString()); //--------------------------------- user.setheadImage((Bitmap)in.readParcelable(Bitmap.class.getClassLoader())); user.setAge(in.readInt()); return user; } public UserInfo[] newArray(int size) { return new UserInfo[size]; } }; static { } @OverrIDe public int describeContents() { return 0; } @OverrIDe public voID writetoParcel(Parcel out,int flags) { out.writeSerializable(ID); out.writeString(phone); out.writeString(username); out.writeString(password); out.writeString(IDCard); out.writeString(email); out.writeString(ActivateCode); out.writeString(Boolean.toString(isActivated)); out.writeSerializable(createDate); out.writeSerializable(activatedDate); //------------------------------- out.writeString(sex); out.writeString(birthday); out.writeString(height); out.writeString(weight); out.writeString(waistline); out.writeString(nickname); //---------------------- out.writeParcelable(headImage,PARCELABLE_WRITE_RETURN_VALUE); out.writeInt(age); }}</userinfo>

这其中，针对头像问题，做了如下修改：

1）将原来Image类型的头像改为Bitmap类型，并设置get和set方法

public voID setheadImage(Bitmap headImage){ this.headImage=headImage; } public Bitmap getheadImage(){ return headImage; }

2）在反序列化部分加入对头像 *** 作的语句

user.setheadImage((Bitmap)in.readParcelable(Bitmap.class.getClassLoader()));

3）在序列化部分加入对头像 *** 作的语句

out.writeParcelable(headImage,PARCELABLE_WRITE_RETURN_VALUE);

接下来要在数据库帮助类UserDbUtil类中对添加用户数据、查询用户数据的方法进行修改，以包含头像部分

该工具类的整体代码如图所示：

public class UserDbUtil extends DatabaseUtil { private Context mContext; public UserDbUtil(Context mContext,boolean Readonly) { super(mContext,Readonly); } /**--------------------------------------------------------------------------------------------------------------------------*/ /**功能：根据手机号码查询用户表里的信息，看哪些为空，是否更新了*/ public voID queryLoginUserInfo(String loginPhone) { Cursor localCursor = this.db.query("T_User","UserPhone=? ",new String[] { loginPhone },null); while (localCursor.movetoNext()){ int quryID=Integer.valueOf(localCursor.getColumnIndex("ID")); String queryphone=localCursor.getString(localCursor.getColumnIndex("UserPhone")); String queryPassword=localCursor.getString(localCursor.getColumnIndex("Password")); String qureyUsername=localCursor.getString(localCursor.getColumnIndex("Username")); String qureyIDCard=localCursor.getString(localCursor.getColumnIndex("IDCard")); String qureyActivateCode=localCursor.getString(localCursor.getColumnIndex("ActivateCode")); String qureyCreateDate=localCursor.getString(localCursor.getColumnIndex("CreateDate")); String qureyEmail=localCursor.getString(localCursor.getColumnIndex("Email")); String qureyNickname=localCursor.getString(localCursor.getColumnIndex("Nickname")); String qureySex=localCursor.getString(localCursor.getColumnIndex("Sex")); String qureyBirthday=localCursor.getString(localCursor.getColumnIndex("Birthday")); String qureyHeight=localCursor.getString(localCursor.getColumnIndex("Height")); String qureyWeight=localCursor.getString(localCursor.getColumnIndex("Weight")); String qureyWaistline=localCursor.getString(localCursor.getColumnIndex("Waistline")); String qureyActivatedDate=localCursor.getString(localCursor.getColumnIndex("ActivatedDate")); int qureyAge=localCursor.getInt(localCursor.getColumnIndex("Age")); //-------------- byte[] in = localCursor.getBlob(localCursor.getColumnIndex("headImage")); if(in!=null){ Bitmap bmpout = BitmapFactory.decodeByteArray(in,in.length); } //------------------------------------------------- System.out.println("ID="+quryID); System.out.println("queryphone="+queryphone); System.out.println("queryPassword="+queryPassword); System.out.println("qureyUsername="+qureyUsername); System.out.println("qureyIDCard="+qureyIDCard); System.out.println("qureyActivateCode="+qureyActivateCode); System.out.println("qureyCreateDate="+qureyCreateDate); System.out.println("qureyEmail="+qureyEmail); System.out.println("qureyNickname="+qureyNickname); System.out.println("qureySex="+qureySex); System.out.println("qureyBirthday="+qureyBirthday); System.out.println("qureyHeight="+qureyHeight); System.out.println("qureyWeight="+qureyWeight); System.out.println("qureyWaistline="+qureyWaistline); System.out.println("qureyActivatedDate="+qureyActivatedDate); System.out.println("qureyAge="+qureyAge); } } /**------------------------------------------------------------------------------------------------------------------*/ /**---------------------------------------------------------------------------------------------*/ /** * 登录时检查密码是否输入错误，并返回一个User对象，作为该APP登录使用的用户名和密码信息*/ public UserInfo login(String loginPhone,String password) { //String str1 = getMD5String(password); Cursor localCursor = this.db.query("T_User","UserPhone=? and Password=?",new String[] { loginPhone,password },null); if (localCursor.getCount() == 0) { Log.d("TC_Log","UserDbUtil -- " + loginPhone + " login Failed"); return null; } localCursor.movetoNext(); UserInfo localUserInfo = new UserInfo(); localUserInfo.setID(Integer.valueOf(localCursor.getInt(localCursor.getColumnIndex("ID")))); localUserInfo.setPhone(localCursor.getString(localCursor.getColumnIndex("UserPhone"))); localUserInfo.setUsername(localCursor.getString(localCursor.getColumnIndex("Username"))); localUserInfo.setIDCard(localCursor.getString(localCursor.getColumnIndex("IDCard"))); localUserInfo.setEmail(localCursor.getString(localCursor.getColumnIndex("Email"))); localUserInfo.setActivateCode(localCursor.getString(localCursor.getColumnIndex("ActivateCode")));//------------------------------------------------------------------------------------------- localUserInfo.setPassword(localCursor.getString(localCursor.getColumnIndex("Password"))); localUserInfo.setNickname(localCursor.getString(localCursor.getColumnIndex("Nickname"))); localUserInfo.setSex(localCursor.getString(localCursor.getColumnIndex("Sex"))); localUserInfo.setBirthday(localCursor.getString(localCursor.getColumnIndex("Birthday"))); localUserInfo.setHeight(localCursor.getString(localCursor.getColumnIndex("Height"))); localUserInfo.setWeight(localCursor.getString(localCursor.getColumnIndex("Weight"))); localUserInfo.setWaistline(localCursor.getString(localCursor.getColumnIndex("Waistline"))); localUserInfo.setAge(localCursor.getInt(localCursor.getColumnIndex("Age"))); /**-添加了头像到T_User表里后所做的修改---------------------------------------------------------------*/ //---------------------------------------------------- byte[] in = localCursor.getBlob(localCursor.getColumnIndex("headImage")); if(in!=null){ Bitmap bmpout = BitmapFactory.decodeByteArray(in,in.length); localUserInfo.setheadImage(bmpout); } //------------------------------------------- if ("1".equals(localCursor.getString(localCursor.getColumnIndex("IsActivated")))) { localUserInfo.setActivated(true); } String str2 = localCursor.getString(localCursor.getColumnIndex("CreateDate")); String str3 = localCursor.getString(localCursor.getColumnIndex("ActivatedDate")); if ((str2 != null) && (str2.equals(""))) { localUserInfo.setCreateDate(AppUtil.string2Date(str2)); } if ((str3 != null) && (str3.equals(""))) { localUserInfo.setActivatedDate(AppUtil.string2Date(str3)); } Log.d("TC_Log","UserDbUtil -- login success,name=" + localUserInfo.getUsername()); localCursor.close(); return localUserInfo; } /**------------------------------------------------------------------------------------------------------------------*/ /**--------------------------------------------------------------------------------------------------------------*/ //登录时，检查输入的手机号在数据库中是否存在，用户名是否存在？ public boolean checkAccount(String phone){ Cursor localCursor = this.db.query("T_User","UserPhone=?",new String[] {phone},null); if (localCursor.getCount()==0) //光标恒=0，也就是说没有查到 { return false; }else { return true; } } /**---注册后下一次登录，检查数据库中是否有存储的手机号----------------------------------------------------------------------------------------------------*/ public UserInfo checkUserDb(){ //Cursor localCursor = this.db.query("T_User","ID=?",new String[] {"1"},null); Cursor localCursor = this.db.query("T_User",null); if (localCursor.getCount()==0) //光标恒=0，也就是说表是空的 { return null; } else { localCursor.movetoNext(); UserInfo localUserInfo = new UserInfo(); localUserInfo.setID(Integer.valueOf(localCursor.getInt(localCursor.getColumnIndex("ID")))); localUserInfo.setPhone(localCursor.getString(localCursor.getColumnIndex("UserPhone"))); localUserInfo.setPassword(localCursor.getString(localCursor.getColumnIndex("Password"))); localCursor.close(); return localUserInfo; } } /**------------------------------------------------------------------------------------------------------*/ /**-----------------------------------------------------------------------------------------------------*/ //-注册时，检查数据库中是否有该手机号码，以免重复 public boolean checkRepetition(String phone){ Cursor localCursor = this.db.query("T_User",null); if (localCursor.getCount()==0) //光标恒=0，也就是说没有查到 { return false; }else { while (localCursor.movetoNext()){ String savePhone=localCursor.getString(localCursor.getColumnIndex("UserPhone")); System.out.println("存储的电话号码为："+savePhone); } return true; } }/**-----------------------------------------------------------------------------------*/ public boolean saveUser(UserInfo user) { try { db.beginTransaction(); delete("T_User",null); //String password = user.getpassword() //String activateCode = user.getActivateCode(); //user.setPassword(getMD5String(password)); //user.setPassword(user.getpassword()); //user.setActivateCode(getMD5String(activateCode)); ContentValues values = getUserContentValues(user); insert("T_User",values); //Log.d("TC_Log",user.getUsername()); db.setTransactionSuccessful(); return true; } catch(Exception ex) { Log.e("TC_Log","UserDbUtil -- saver user error",ex); return false; } finally { db.endTransaction(); } } /**----------------------------------------------------------------------------------*/ /**填写健康档案后，更新用户信息*/ public boolean updateUserInfo(UserInfo user){ try { ContentValues values=getUserContentValues(user); update("T_User",values,user.getPhone(),null); return true; }catch (Exception e){ Log.e("TC_Log","UserDbUtil -- update userInfo error",e); return false; } }/**------------------------------------------------------------------------------*/ public String getPhoneInDB() { Cursor cursor = db.query("T_User",new String[]{"UserPhone"},null); if(cursor.getCount() != 1) { cursor.close(); return null; } cursor.movetoNext(); String phone = cursor.getString(0); cursor.close(); return phone; } public boolean doActivate(String phone,String activateCode) { Cursor localCursor = this.db.query("T_User",new String[]{"ActivateCode"},new String[]{phone},null); if (localCursor.getCount() == 0) { localCursor.close(); return false; } localCursor.movetoNext(); boolean bool = localCursor.getString(localCursor.getColumnIndex("ActivateCode")).equals(getMD5String(activateCode)); if (bool) { ContentValues localContentValues = new ContentValues(); localContentValues.put("ActivatedDate",AppUtil.date2String(new Date())); localContentValues.put("IsActivated","1"); update("T_User",localContentValues,new String[] { phone }); Log.d("TC_Log","UserDbUtil -- activate success"); } localCursor.close(); return bool; } public boolean saveActivateCode(String phone,boolean needReactivate) { String code = getMD5String(activateCode); ContentValues cvCode = new ContentValues(); cvCode.put("ActivateCode",code); cvCode.put("Password",code); if(needReactivate) { cvCode.put("IsActivated",Integer.valueOf(0)); } update("T_User",cvCode,new String[]{phone}); return true; } public String getTryOutTime(String phone) { Cursor localCursor = this.db.query("T_User",new String[] { "CreateDate" },new String[] { phone },null); if (localCursor.getCount() == 0) { localCursor.close(); return null; } localCursor.movetoNext(); String str = localCursor.getString(0); long l1 = AppUtil.string2Date(str).getTime(); long l2 = l1 + 2592000000L; Log.d("TC_Log","UserDbUtil -- getTryOutTime:create time=" + str + "," + l1); Log.d("TC_Log","UserDbUtil -- getTryOutTime:due times=" + l2); Log.d("TC_Log","UserDbUtil -- getTryOutTime:Now times=" + new Date().getTime()); int i = (int)((l2 - new Date().getTime()) / 1000L); Log.d("TC_Log","UserDbUtil -- getTryOutTime:seconds=" + i); if (i <= 0) { localCursor.close(); return "PastDue"; } int j = i / 86400; int k = (i - 24 * (j * 3600)) / 3600; int m = (i - 24 * (j * 3600) - k * 3600) / 60; localCursor.close(); StringBuilder localStringBuilder = new StringBuilder(); localStringBuilder.append(j); localStringBuilder.append(" "); localStringBuilder.append(this.mContext.getString(R.string.user_remain_time_day1)); localStringBuilder.append(k); localStringBuilder.append(" "); localStringBuilder.append(this.mContext.getString(R.string.user_remain_time_hour1)); localStringBuilder.append(m); localStringBuilder.append(" "); localStringBuilder.append(this.mContext.getString(R.string.user_remain_time_minute1)); return localStringBuilder.toString(); } public boolean isTryTimeout(String phone) { Cursor localCursor = this.db.query("T_User",new String[]{"CreateDate"},null); if (localCursor.getCount() == 0) { localCursor.close(); return true; } localCursor.movetoNext(); String str = localCursor.getString(0); long l1 = AppUtil.string2Date(str).getTime(); long l2 = l1 + 2592000000L; Log.d("TC_Log","UserDbUtil -- getTryOutTime:seconds=" + i); localCursor.close(); return i <= 0; } public UserInfo getCurrentUser() { Cursor cursor = db.query("T_User",null); if(cursor.getCount() != 1) { Log.w("TC_Log","UserDbUtil -- no unique user info!!user count=" + cursor.getCount()); cursor.close(); return null; } cursor.movetoNext(); UserInfo user = new UserInfo(); user.setID(Integer.valueOf(cursor.getInt(cursor.getColumnIndex("ID")))); user.setPhone(cursor.getString(cursor.getColumnIndex("UserPhone"))); user.setUsername(cursor.getString(cursor.getColumnIndex("Username"))); user.setIDCard(cursor.getString(cursor.getColumnIndex("IDCard"))); user.setEmail(cursor.getString(cursor.getColumnIndex("Email"))); user.setActivateCode(cursor.getString(cursor.getColumnIndex("ActivateCode"))); String isActivate = cursor.getString(cursor.getColumnIndex("IsActivated")); //------------------------------------------------------------------------------------------- user.setPassword(cursor.getString(cursor.getColumnIndex("Password"))); user.setNickname(cursor.getString(cursor.getColumnIndex("Nickname"))); user.setSex(cursor.getString(cursor.getColumnIndex("Sex"))); user.setBirthday(cursor.getString(cursor.getColumnIndex("Birthday"))); user.setHeight(cursor.getString(cursor.getColumnIndex("Height"))); user.setWeight(cursor.getString(cursor.getColumnIndex("Weight"))); user.setWaistline(cursor.getString(cursor.getColumnIndex("Waistline"))); //------------------------------------------- byte[] in = cursor.getBlob(cursor.getColumnIndex("headImage")); if(in!=null){ Bitmap bmpout = BitmapFactory.decodeByteArray(in,in.length); user.setheadImage(bmpout); } //--------------------------------------------------- user.setAge(cursor.getInt(cursor.getColumnIndex("Age"))); //-------------------------------------------------------------------------- if("1".equals(isActivate)) { user.setActivated(true); } String createDate = cursor.getString(cursor.getColumnIndex("CreateDate")); String activateDate = cursor.getString(cursor.getColumnIndex("ActivatedDate")); if((createDate != null) && (createDate.equals(""))) { user.setCreateDate(AppUtil.string2Date(createDate)); } if((activateDate != null) && (activateDate.equals(""))) { user.setActivatedDate(AppUtil.string2Date(activateDate)); } cursor.close(); return user; } public boolean getautoLogin() { Cursor localCursor = this.db.query("T_SystemParameter",new String[] { "ParamValue" },"ParamKey=?",new String[] { "autoLogin" },null); if (localCursor.getCount() != 1) { Log.e("TC_Log","SystemParameterDbUtil -- getautoLogin: autoSync error"); localCursor.close(); return false; } localCursor.movetoNext(); String str = localCursor.getString(0); localCursor.close(); boolean bool = str.equals("1"); Log.d("TC_Log","SystemParameterDbUtil -- getautoLogin:" + bool); return bool; } private ContentValues getUserContentValues(UserInfo user) { ContentValues cvUser = new ContentValues(); if(user.getPhone() != null) { cvUser.put("UserPhone",user.getPhone()); System.out.println("插入的电话是" + user.getPhone()); } if(user.getUsername() != null) { cvUser.put("Username",user.getUsername()); } if(user.getpassword() != null) { cvUser.put("Password",user.getpassword()); } if(user.getIDCard() != null) { cvUser.put("IDCard",user.getIDCard()); } if(user.getEmail() != null) { cvUser.put("Email",user.getEmail()); } if(user.getActivateCode() != null) { cvUser.put("ActivateCode",user.getActivateCode()); } if(user.isActivated()) { cvUser.put("IsActivated","1"); } else { cvUser.put("IsActivated","0"); } if(user.getCreateDate() != null) { cvUser.put("CreateDate",AppUtil.date2String(user.getCreateDate())); } if(user.getActivatedDate() != null) { cvUser.put("ActivatedDate",AppUtil.date2String(user.getActivatedDate())); } if(user.getAge() >= 0) { cvUser.put("Age",Integer.valueOf(user.getAge())); } //------------------------------------------------------- //健康档案中添加的数据 if(user.getSex() != null) { cvUser.put("Sex",user.getSex()); } if(user.getBirthday() != null) { cvUser.put("Birthday",user.getBirthday()); } if(user.getHeight() != null) { cvUser.put("Height",user.getHeight()); } if(user.getWeight() != null) { cvUser.put("Weight",user.getWeight()); } if(user.getWaistline() != null) { cvUser.put("Waistline",user.getWaistline()); } if(user.getNickname() != null) { cvUser.put("Nickname",user.getNickname()); } /**-添加了头像到表T_User里面后作的修改---------------------------------------------*/ //--------------------- if(user.getheadImage()!=null){ cvUser.put("headImage",headimg(user.getheadImage())); } return cvUser; } //------------------------------------------------------------------- /**功能模块：将头像图片存储在本地数据库 * 时间：2016.01.06 * 作者：黄永红*/ /*-将图片转化为 byte[]---------------------------------------------------------------------------------------------*/ public byte[] headimg(Bitmap bm){ ByteArrayOutputStream baos = new ByteArrayOutputStream(); bm.compress(Bitmap.CompressFormat.PNG,baos); return baos.toByteArray(); } /*public long insert(byte[] img){ //databaseHelper dbhelper =new databaseHelper(UserDetailinformation01Activity.this,2); databaseHelper dbhelper =new databaseHelper(UserDetailinformation01Activity.this,2); sqliteDatabase db = dbhelper.getWritableDatabase(); // sqliteDatabase db = databaseHelper.getInstance(UserDetailinformation01Activity.this).getWritableDatabase(); ContentValues values =new ContentValues(); values.put("headImage",img); //把最新设置的头像值插入表中一行 long result = db.insert("My_UserInfo",values); savetouxiang=true; db.close(); return result; }*/ //------------------------------------------------------------------- public boolean isPasswordRight(String pwd) { String md5Pwd = getMD5String(pwd); Cursor cursor = db.query("T_User",new String[] {"Password"},null); if(cursor.getCount() != 1) { Log.e("TC_Log","UserDbUtil -- isPasswordRight: no unique user"); cursor.close(); return false; } cursor.movetoNext(); String pwdindb = cursor.getString(0); return md5Pwd.equals(pwdindb); } private String getMD5String(String code) { try { char[] arrayOfChar1 = { 48,49,50,51,52,53,54,55,56,57,97,98,99,101,102 }; byte[] arrayOfByte1 = code.getBytes(); MessageDigest localMessageDigest = MessageDigest.getInstance("MD5"); localMessageDigest.update(arrayOfByte1); byte[] arrayOfByte2 = localMessageDigest.digest(); char[] arrayOfChar2 = new char[2 * arrayOfByte2.length]; int j = 0; for (int i=0;i<arrayofbyte2 length="" i="" int="" k="arrayOfByte2[i];" int="" m="j" 1="" arrayofchar2="" j="" arrayofchar1="" 0xf="" k="">> 4)]; j = m + 1; arrayOfChar2[m] = arrayOfChar1[(k & 0xF)]; } return new String(arrayOfChar2); } catch (Exception localException) { localException.printstacktrace(); return null; } }}</arrayofbyte2>

一切调整完毕，下载一运行，。。。。运行停止！

看logcat信息显示是空指针异常，定位了半天，原来是这里代码有误啊

/**-添加了头像到表T_User里面后作的修改---------------------------------------------*/ //--------------------- if(headimg(user.getheadImage())!=null){ cvUser.put("headImage",headimg(user.getheadImage())); }//----------------------------------- /*-将图片转化为 byte[]---------------------------------------------------------------------------------------------*/ public byte[] headimg(Bitmap bm){ ByteArrayOutputStream baos = new ByteArrayOutputStream(); bm.compress(Bitmap.CompressFormat.PNG,baos); return baos.toByteArray(); }

这里，完全没有考虑user.getheadImage()就可能为null的情况，造成了headimg(Bitmap bm)空指针。找到问题，改就容易了：

/**-添加了头像到表T_User里面后作的修改---------------------------------------------*/ //--------------------- if(user.getheadImage()!=null){ cvUser.put("headImage",baos); return baos.toByteArray(); }

--------------------------------------------------------------------------------------

心里想，这下该好了吧。添加健康档案，一提交，啪，运行又停止了。一看logcat，还是空指针！

心里万马奔腾啊！尼玛，不就是两三个月没编程了吗，至于搞成这样，连续两处空指针！亏得我准备面试，编小程序的时候，还每次就预防着空指针呢，怎么到了项目上，真实一点儿没发现呢。赶紧查！

看吧，是在登录时获取头像信息没检查空指针：

/**---------------------------------------------------------------------------------------------*/ /** * 登录时检查密码是否输入错误，并返回一个User对象，作为该APP登录使用的用户名和密码信息*/ public UserInfo login(String loginPhone,"UserDbUtil -- " + loginPhone + " login Failed"); return null; } localCursor.movetoNext(); UserInfo localUserInfo = new UserInfo(); localUserInfo.setID(Integer.valueOf(localCursor.getInt(localCursor.getColumnIndex("ID")))); localUserInfo.setPhone(localCursor.getString(localCursor.getColumnIndex("UserPhone"))); localUserInfo.setUsername(localCursor.getString(localCursor.getColumnIndex("Username"))); localUserInfo.setIDCard(localCursor.getString(localCursor.getColumnIndex("IDCard"))); localUserInfo.setEmail(localCursor.getString(localCursor.getColumnIndex("Email"))); localUserInfo.setActivateCode(localCursor.getString(localCursor.getColumnIndex("ActivateCode")));//------------------------------------------------------------------------------------------- localUserInfo.setPassword(localCursor.getString(localCursor.getColumnIndex("Password"))); localUserInfo.setNickname(localCursor.getString(localCursor.getColumnIndex("Nickname"))); localUserInfo.setSex(localCursor.getString(localCursor.getColumnIndex("Sex"))); localUserInfo.setBirthday(localCursor.getString(localCursor.getColumnIndex("Birthday"))); localUserInfo.setHeight(localCursor.getString(localCursor.getColumnIndex("Height"))); localUserInfo.setWeight(localCursor.getString(localCursor.getColumnIndex("Weight"))); localUserInfo.setWaistline(localCursor.getString(localCursor.getColumnIndex("Waistline"))); localUserInfo.setAge(localCursor.getInt(localCursor.getColumnIndex("Age"))); /**-添加了头像到T_User表里后所做的修改---------------------------------------------------------------*/ //---------------------------------------------------- byte[] in = localCursor.getBlob(localCursor.getColumnIndex("headImage")); Bitmap bmpout = BitmapFactory.decodeByteArray(in,in.length); localUserInfo.setheadImage(bmpout); //------------------------------------------- if ("1".equals(localCursor.getString(localCursor.getColumnIndex("IsActivated")))) { localUserInfo.setActivated(true); } String str2 = localCursor.getString(localCursor.getColumnIndex("CreateDate")); String str3 = localCursor.getString(localCursor.getColumnIndex("ActivatedDate")); if ((str2 != null) && (str2.equals(""))) { localUserInfo.setCreateDate(AppUtil.string2Date(str2)); } if ((str3 != null) && (str3.equals(""))) { localUserInfo.setActivatedDate(AppUtil.string2Date(str3)); } Log.d("TC_Log",name=" + localUserInfo.getUsername()); localCursor.close(); return localUserInfo; }

没看出来，好吧，非得让我暴露得彻彻底底的。

byte[] in = localCursor.getBlob(localCursor.getColumnIndex("headImage")); Bitmap bmpout = BitmapFactory.decodeByteArray(in,in.length); localUserInfo.setheadImage(bmpout);

看什么，赶紧改吧，说多了都是泪啊！

修改后的代码如下：

/**-添加了头像到T_User表里后所做的修改---------------------------------------------------------------*/ //---------------------------------------------------- byte[] in = localCursor.getBlob(localCursor.getColumnIndex("headImage")); if(in!=null){ Bitmap bmpout = BitmapFactory.decodeByteArray(in,in.length); localUserInfo.setheadImage(bmpout); }

至此，终于把这个小功能的空指针异常给改完了！吸取教训，这人啊，往往死在最不起眼的细节上面，说的就是我们这些苦逼的程序员，尤其是正在进阶中的程序员！共勉啊！

总结

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