怎样在Java实例开发的过程中使用进度条_教程

在读取大型文件或者其它大批量数据输入 *** 作时希望能够通过一个进度条显示当前的进度现在在Java中非常容易实现仅仅需要几行代码即可 Java的swing包提供了ProgressMonitorInputStream类该类提供了自动地d出进度窗口和事件处理机制使用这个类也非常方便只需要把任何一个InputStream作为参数构造一个新的ProgressMonitorInputStream类其它不需要任何额外的代码即可实现进度窗口的自动生成 ProgressMonitorInputStream类可以和其它InputStream一样使用 ProgressMonitorInputStream类继承层次 [pre]java lang Object|+ java io InputStream|+ java io FilterInputStream|+ javax swing ProgressMonitorInputStream[/pre] 构造方法携尺拦ProgressMonitorInputStream(Component parentComponent Object message InputStream in)parentComponent 触发被监视 *** 作的组件message (如果d出进度显示窗口) 显示在进度显示窗口中的指示信辩胡息in 需要监视的输入流 *** 作方法除了在InputStream和FilterInputStream中继承的方法外还增加了如下方法 ProgressMonitor getProgressMonitor()//得到当前对象使用的ProgressMonitor对象 int read()int read(byte[] b)int read(byte[] b int off int len)void reset()long skip(long n)//上面几个方法都是覆盖了FilterInputStream中的方法困码因为需要更新进度指示 void close()//因为需要关闭进度监视对象和窗口所以覆盖了FilterInputStream父类中的close方法示例代码: import java awt FlowLayoutimport java awt event ActionEventimport java awt event ActionListenerimport java io FileInputStreamimport java io InputStreamimport javax swing JButtonimport javax swing JFrameimport javax swing ProgressMonitorInputStreampublic class ProgressMonitorTest{public static void main(String[] args){// 创建一个包含 Click me 的窗口final JFrame f =new JFrame( ProgressMonitor Sample )f getContentPane() setLayout(new FlowLayout())JButton b = new JButton( Click me )f getContentPane() add(b)f pack()// 设置按钮的动作事件b addActionListener(new ActionListener(){public void actionPerformed(ActionEvent e){// 这儿使用了新的线程处理按钮的动作事件因为我们需要//主窗口的线程响应用户这样你可以多次点击该按钮 //会启动多个读取文件的线程主窗口也保持响应 new Thread(){public void run(){try {// 打开文件输出流把InputStream包装在ProgressMonitorInputStream中 //在当前目录中需要放置一个大文件建议超过 MInputStream in = new FileInputStream( bigfile dat )ProgressMonitorInputStream pm =new ProgressMonitorInputStream(f Reading a big file in)// 读取文件如果总耗时超过秒将会自动d出一个进度监视窗口 //　显示已读取的百分比 int cwhile((c=pm read()) != ){// 处理代码}pm close()}catch(Exception ex){ex printStackTrace()}}} start()}})// 设置缺省的窗口关闭行为并显示窗口 f setDefaultCloseOperation(JFrame EXIT_ON_CLOSE)f setVisible(true)}} lishixinzhi/Article/program/Java/hx/201311/25629

使用 apache fileupload ,spring MVC jquery1.6x , bootstrap 实现一个带进度条的多文件上传，由于旁谈fileupload 的局限，暂不能实现每个上传文件都显示进度条，只能实现一个总的进度条，效果如图：

1、jsp 页面

<!DOCTYPE html>

<%@ page contentType="text/htmlcharset=UTF-8"%>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<head>

</head>

<body>

<form id='fForm' class="form-actions form-horizontal" action="../upload.html"

encType="multipart/form-data" target="uploadf" method="post">

</div>

<型孙input type="file" name="file" style="width:550">

</div>

</div>

卜启链 <div id = 'proBar' class="bar" style="width: 0%"></div>

</div>

<button type="button" id="subbut" class="btn">submit</button>

</div>

</form>

</body>

</html>

$(document).ready(function(){

$('#subbut').bind('click',

function(){

$('#fForm').submit()

var eventFun = function(){

$.ajax({

type: 'GET',

url: '../process.json',

data: {},

dataType: 'json',

success : function(data){

$('#proBar').css('width',data.rate+''+'%')

$('#proBar').empty()

$('#proBar').append(data.show)

if(data.rate == 100){

window.clearInterval(intId)

}

}})}

var intId = window.setInterval(eventFun,500)

})

</script>

2、java 代码

package com.controller

import java.util.List

import javax.servlet.http.HttpServletRequest

import javax.servlet.http.HttpServletResponse

import javax.servlet.http.HttpSession

import org.apache.commons.fileupload.FileItemFactory

import org.apache.commons.fileupload.ProgressListener

import org.apache.commons.fileupload.disk.DiskFileItemFactory

import org.apache.commons.fileupload.servlet.ServletFileUpload

import org.apache.log4j.Logger

import org.springframework.stereotype.Controller

import org.springframework.web.bind.annotation.RequestMapping

import org.springframework.web.bind.annotation.RequestMethod

import org.springframework.web.bind.annotation.ResponseBody

import org.springframework.web.servlet.ModelAndView

@Controller

public class FileUploadController {

Logger log = Logger.getLogger(FileUploadController.class)

/**

* upload 上传文件

* @param request

* @param response

* @return

* @throws Exception

@RequestMapping(value = "/upload.html", method = RequestMethod.POST)

public ModelAndView upload(HttpServletRequest request,

HttpServletResponse response) throws Exception {

final HttpSession hs = request.getSession()

ModelAndView mv = new ModelAndView()

boolean isMultipart = ServletFileUpload.isMultipartContent(request)

if(!isMultipart){

return mv

}

// Create a factory for disk-based file items

FileItemFactory factory = new DiskFileItemFactory()

// Create a new file upload handler

ServletFileUpload upload = new ServletFileUpload(factory)

upload.setProgressListener(new ProgressListener(){

public void update(long pBytesRead, long pContentLength, int pItems) {

ProcessInfo pri = new ProcessInfo()

pri.itemNum = pItems

pri.readSize = pBytesRead

pri.totalSize = pContentLength

pri.show = pBytesRead+"/"+pContentLength+" byte"

pri.rate = Math.round(new Float(pBytesRead) / new Float(pContentLength)*100)

hs.setAttribute("proInfo", pri)

}

})

List items = upload.parseRequest(request)

// Parse the request

// Process the uploaded items

// Iterator iter = items.iterator()

// while (iter.hasNext()) {

// FileItem item = (FileItem) iter.next()

// if (item.isFormField()) {

// String name = item.getFieldName()

// String value = item.getString()

// System.out.println("this is common feild!"+name+"="+value)

// } else {

// System.out.println("this is file feild!")

// String fieldName = item.getFieldName()

// String fileName = item.getName()

// String contentType = item.getContentType()

// boolean isInMemory = item.isInMemory()

// long sizeInBytes = item.getSize()

// File uploadedFile = new File("c://"+fileName)

// item.write(uploadedFile)

// }

return mv

}

/**

* process 获取进度

* @param request

* @param response

* @return

* @throws Exception

@RequestMapping(value = "/process.json", method = RequestMethod.GET)

@ResponseBody

public Object process(HttpServletRequest request,

HttpServletResponse response) throws Exception {

return ( ProcessInfo)request.getSession().getAttribute("proInfo")

}

class ProcessInfo{

public long totalSize = 1

public long readSize = 0

public String show = ""

public int itemNum = 0

public int rate = 0

}

代洞雀码如下：import java.awt.Colorimport java.awt.Toolkitimport javax.swing.ImageIconimport javax.swing.JLabelimport javax.swing.JOptionPaneimport javax.swing.JProgressBarimport javax.swing.JWindow@SuppressWarnings("serial") public class Demo extends JWindow implements Runnable { // 定义加载窗口大小 public static final int LOAD_WIDTH = 455public static final int LOAD_HEIGHT = 295// 获取屏幕窗口大小 public static final int WIDTH = Toolkit.getDefaultToolkit().getScreenSize().widthpublic static final int HEIGHT = Toolkit.getDefaultToolkit().getScreenSize().height// 定义进度条组件 public JProgressBar progressbar// 定义标签组件 public JLabel label// 构造函数 public Demo() { // 创建标签,并在标签上放置一张图片 label = new JLabel(new ImageIcon("images/background.jpg"))label.setBounds(0, 0, LOAD_WIDTH, LOAD_HEIGHT - 15)//冲中创建进度条 progressbar = new JProgressBar()// 显示当前进度值信纳判早息 progressbar.setStringPainted(true)// 设置进度条边框不显示 progressbar.setBorderPainted(false)// 设置进度条的前景色 progressbar.setForeground(new Color(0, 210, 40))// 设置进度条的背景色 progressbar.setBackground(new Color(188, 190, 194))progressbar.setBounds(0, LOAD_HEIGHT - 15, LOAD_WIDTH, 15)// 添加组件 this.add(label)this.add(progressbar)// 设置布局为空 this.setLayout(null)// 设置窗口初始位置 this.setLocation((WIDTH - LOAD_WIDTH) / 2, (HEIGHT - LOAD_HEIGHT) / 2)// 设置窗口大小 this.setSize(LOAD_WIDTH, LOAD_HEIGHT)// 设置窗口显示 this.setVisible(true)} public static void main(String[] args) { Demo t = new Demo()new Thread(t).start()} @Override public void run() { for (int i = 0i <100i++) { try { Thread.sleep(100)} catch (InterruptedException e) { e.printStackTrace()} progressbar.setValue(i)} JOptionPane.showMessageDialog(this, "加载完成")this.dispose()} } 效果图：

欢迎分享，转载请注明来源：内存溢出

原文地址: http://outofmemory.cn/tougao/12227847.html

怎样在Java实例开发的过程中使用进度条

发表评论

评论列表（0条）