2、找到相应的数据库连接包,sql、oracle都有对应的jar包;
2、写一个类,结合对应的jar包来连接数据库;
3、再写一个类,通过第二步的类用来对数据库 *** 作。
其实是比较简单的。
数据库内容
java源代码 (代码实现的是查询成绩为 的人员信息 至于其他功能的 代码中有注释) 注意 在eclipse里运行程序的时候 要工程里插入jar包 否则运行异常! import java sql *import java io *class database_manage { public Connection conn = null public ResultSet rs = null private String DatabaseDriver = " mysql jdbc Driver" // DataSource 数据源名称DSN private String DatabaseConnStr = "jdbc:mysql://localhost: /people_manage?useUnicode=true&characterEncoding=utf " + " root root" public void setDatabaseDriver(String Driver) { this DatabaseDriver = Driver } public String getDatabaseDriver() { return (this DatabaseDriver) } public void setDatabaseConnStr(String ConnStr) { this DatabaseConnStr = ConnStr } public String getDatabaseConnStr() { return (this DatabaseConnStr) } public database_manage() {// 构造函数连接数据库 try { Class forName(DatabaseDriver)} catch (java lang ClassNotFoundException e) { System err println("加载驱动器有错误:" + e getMessage()) System out print("执行插入有错误:" + e getMessage())// 输出到客户端 } } public ResultSet query(String sql) {// 查询数据库 rs = nulltry { conn = DriverManager getConnection( "jdbc:mysql://localhost: /people_manage?useUnicode=true&characterEncoding=utf " "root" "root") Statement stmt = conn createStatement() rs = stmt executeQuery(sql)} catch (SQLException ex) { System err println("执行查询有错误:" + ex getMessage()) System out print("执行查询有错误:" + ex getMessage())// 输出到客户端 }return rs
} public int update_database(String sql) {// 更新或插入数据库 int num = try { conn = DriverManager getConnection( "jdbc:mysql://localhost: /people_manage?useUnicode=true&characterEncoding=utf " "root" "root") Statement stmt = conn createStatement() num = stmt executeUpdate(sql)} catch (SQLException ex) { System err println("执行插入有错误:" + ex getMessage()) System out print("执行插入有错误:" + ex getMessage())// 输出到客户端 } CloseDataBase()return num } public void CloseDataBase() {// 关闭数据库 try { conn close()} catch (Exception end) { System err println("执行关闭Connection对象有错误 " + end getMessage()) System out print("执行执行关闭Connection对象有错误 有错误:" + end getMessage())// 输出到客户端 } } } class people { private String uid private String name private String banji private int score public people() { } public people(String uid String name String banji) { this uid = uidthis name = namethis banji = banji } public people(String uid String name String banji int score) { this uid = uidthis name = namethis banji = banjithis score = score } public String getUid() { return uid } public void setUid(String uid) { this uid = uid } public String getName() { return name } public void setName(String name) { this name = name } public String getBanji() { return banji } public void setBanji(String banji) { this banji = banji } public int getScore() { return score } public void setScore(int score) { this score = score } } public class manage { private people[] people_array // 对象数组 public void add_people(String uid String name) { String sql = "insert people (uid name) values ( " + uid + " " + name + " )"// sql插入语句 // String sql = "insert people (uid name) values ( uid tom )" database_manage db_obj = new database_manage()db_obj update_database(sql) } public void update_people(String uid String name) { String sql = "update people set name= " + name + " where uid= " + uid + " "database_manage db_obj = new database_manage()db_obj update_database(sql) } public void delete_people(String uid) { String sql = "delete from people where uid= " + uid + " " database_manage db_obj = new database_manage() db_obj update_database(sql) } public people query_people(String uid) { database_manage db_obj = new database_manage()// String adminid=nullString uid_new name banjiuid_new = nullname = nullbanji = nullString sql_query = "select * from people where uid= " + uid + " " try { ResultSet rs = db_obj query(sql_query) if (rs next()) { uid_new = rs getString("uid")name = rs getString("name")banji = rs getString("banji") } } catch (Exception e) { e getMessage()} people new_people = new people(uid_new name banji)return new_people } public people[] query_people_byscore(int score) { database_manage db_obj = new database_manage()String uid_new name banjiuid_new = nullname = nullbanji = nullint score_new =String sql_query = "select * from people where score=" + score// sql查询语句
try {
ResultSet rs = db_obj query(sql_query)// 查询后 返回结果集
int num =
ResultSet rs_new = rs
while (rs_new next()) {// 统计结果集中学生个数
num++
}
// System out println(num)
people_array = new people[num]
int i =
rs beforeFirst()// 返回结果集的开始
while (rs next()) {
uid_new = rs getString("uid")
name = rs getString("name")
banji = rs getString("banji")
score_new = rs getInt("score")
people_array [i] = new people(uid_new name banji score_new)
i++
}
} catch (Exception e) {
e getMessage()
}
return people_array
}
public static void main(String args[]) {
/*
* people new_people=new people()
*
* manage mr=new manage()//mr add_people(" " "小明")插入一个学生的信息
*
* new_people=mr query_people(" ")//查询uid= 的学生信息 返回对象 System out
* println(""+new_people getName()+" "+new_people getBanji())
* mr update_people(" " "小王")更新一个学生的信息
*
* new_people=mr query_people(" ")//更新后查询
*
* System out println(""+new_people getName()+" "+new_people getBanji(
* ))
*/
manage mr = new manage()
// mr delete_people(" ")删除uid= 的学生信息
people[] people_array// 声明对象数组
people_array = mr query_people_byscore( )// 返回成绩为一百的学生类数组 后输出
int num =
num = people_array length
for (int i = i <numi++) {
System out println(people_array[i] getUid() + " "
+ people_array[i] getName() + " "
+ people_array[i] getBanji() + " "
+ people_array[i] getScore())
}
}
}
lishixinzhi/Article/program/Java/JSP/201311/20030
Java培训课程内容可能因机构和课程类型而有所不同,但一般而言,Java培训课程通常包括以下内容:
Java基础知识:Java语言基础,包括数据类型、变量、运算符、流程控制、数组、面向对象编程、异常处理等。
Java标准库:Java中常用的类和方法,例如字符串、集合框架、输入/输出、多线程、网络编程等。
Java开发工具:Java开发工具,如Eclipse、IntelliJ IDEA、NetBeans等,以及如何使用这些工具来开发Java程序。
Web开发:Java在Web开发中的应用,如Servlet、JSP、JavaServer Faces(JSF)等框架,以及使用Spring和Hibernate等开源框架。
数据库:Java应用程序通常需要与数据库进行交互,Java培训课程通常会教授如何使用Java中的JDBC API来连接数据库,并使用SQL语言进行数据库 *** 作。
测试和调试:Java开发中测试和调试的基础知识和工具,如JUnit和Log4j等。
其他相关技术:Java培训课程还可能涉及其他与Java相关的技术,如XML、Web服务、Restful API等。
除了以上内容,Java培训课程可能还会包括项目实战和实践,例如开发Web应用程序或其他实际应用程序,以帮助学员将所学知识应用到实际项目中。
总之,Java培训课程旨在使学员掌握Java编程语言及其应用,从而能够开发出高质量的Java应用程序。
想要系统学习,你可以考察对比一下开设有相关专业的热门学校,好的学校拥有根据当下企业需求自主研发课程的能力,能够在校期间取得大专或本科学历,中博软件学院、南京课工场、南京北大青鸟等开设相关专业的学校都是不错的,建议实地考察对比一下。
祝你学有所成,望采纳。
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