//对下载资源处理package index.download;public class StartDownload { public void startLoad(Source source){ try{ int fileLength=source.getFileLength(); int numberPerThread=fileLength/4; for(int i=0;i<4;i++){ int length=numberPerThread; if(i==3){ length=fileLength-i*numberPerThread; } Part part=new Part(i*numberPerThread,length); source.getParts().add(part); DownloadThread downloadThread=new DownloadThread(source,part); downloadThread.start(); }
package index;import index.download.*;import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.io.File;
public class NewTaskFrame extends JFrame{
/**
*
*/
private static final long serialVersionUID = 1L;
private JLabel label1;
private JTextField textField1;
private JLabel label2;
private JTextField textField2;
private JLabel label3;
private JTextField textField3;
private JButton button1;
//private JLabel label4;
//private JComboBox combox;
private JButton button2;
private JButton button3;
private String urlAdress;
private String fileName;
private String savePath;
//private int threadCount;
private JFileChooser fileChooser;
public NewTaskFrame(){
setLayout(null);
label1=new JLabel("下载地址:");
label1.setBounds(30,50,55,20);
label2=new JLabel("保存目录");
label2.setBounds(30,85,55,20);
label3=new JLabel("文件名:");
label3.setBounds(30,120,55,20);
/*label4=new JLabel("线程数:");
label4.setBounds(30,155,50,20);*/
textField1=new JTextField(30);
textField1.setBounds(100,50,400,20);
textField2=new JTextField(System.getProperty("user.home"),22);
textField2.setBounds(100,85,400,20);
textField3=new JTextField(5);
textField3.setBounds(100,120,290,20);
button1=new JButton("选择目录");
button1.setBounds(420,120,80,20);
/*combox=new JComboBox();
for(int i=1;i<=4;i++){
combox.addItem(i);
}
combox.setBounds(100,155,50,20);*/
button2=new JButton("确定");
button2.setBounds(200,190,65,30);
button3=new JButton("取消");
button3.setBounds(330,190,65,30);
add(label1);
add(textField1);
add(textField2);
add(textField3);
add(button1);
//add(combox);
add(label1);
add(label2);
add(label3);
//add(label4);
add(button2);
add(button3);
//添加按钮事件
button2.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
if(textField1.getText().equals(""))
JOptionPane.showMessageDialog(null,"下载地址不能为空！");
else{
urlAdress=textField1.getText();
//System.out.println(urlAdress);
}
if(textField3.getText().equals("")){
JOptionPane.showMessageDialog(null,"文件名不能为空！");
}
else{
fileName=textField3.getText();
//System.out.println(fileName);
}
savePath=textField2.getText();
Source source=new Source(urlAdress,savePath,fileName);
Context.downloadContent.sources.add(source);
Context.startDownload.startLoad(source);
setVisible(false);
}
});
button3.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
setVisible(false);
}
});
button1.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
if(fileChooser==null)
fileChooser=new JFileChooser(new File(System.getProperty("user.home")));
fileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY); fileChooser.showOpenDialog(null);
fileChooser.setCurrentDirectory(fileChooser.getSelectedFile());
textField2.setText(fileChooser.getSelectedFile().getAbsolutePath());
}
});
try{
javax.swing.UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
}catch(Exception e){
e.printStackTrace();
} setTitle("新建下载任务");
setResizable(false);
Dimension screen=Toolkit.getDefaultToolkit().getScreenSize();
setBounds(screen.width/4,screen.height/4,590,300);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
}
public void startLoad(Source source){
try{
int fileLength=source.getFileLength();
int numberPerThread=fileLength/4;
for(int i=0;i<4;i++){
int length=numberPerThread;
if(i==3){
length=fileLength-i*numberPerThread;
}
Part part=new Part(i*numberPerThread,length);
source.getParts().add(part);
DownloadThread downloadThread=new DownloadThread(source,part);
downloadThread.start();
}
}
catch(Exception e){
e.printStackTrace();
}
}
}
package index.download;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
class DownloadThread extends Thread{
private URL url=null;
private InputStream is;
private RandomAccessFile raf;
private Source source;
private Part part;
public DownloadThread(Source source,Part part){
this.source=source;
this.part=part;
try {
raf=new RandomAccessFile(source.getSavePath()+File.separator+part.getPartName(),"rw");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void run(){
try {
url=new URL(source.getUrlAddress());
} catch (MalformedURLException e2) {
// TODO Auto-generated catch block
e2.printStackTrace();
}
byte [] buf=new byte[32];
int perRead=0;
try {
URLConnection connection=url.openConnection();
connection.connect();
is=connection.getInputStream();
is.skip(part.getStart()+part.getCurrentLoad());
raf.seek(part.getCurrentLoad());
int per=0;
while((perRead=is.read(buf))!=-1){
per += perRead;
if(per>=32){
raf.write(buf,0,32-(part.getLength()-per));
break;
}
raf.write(buf,0,perRead);
part.setCurrentLoad(part.getCurrentLoad()+perRead);
}
if(isFinish(source))
merger(source);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try{
if(is!=null)
is.close();
if(raf!=null)
raf.close();
}
catch(IOException e){
e.printStackTrace();
}
}
public boolean isFinish(Source source){
int totalLoad=0;
ArrayList<Part> parts=source.getParts();
for(Part part : parts){
totalLoad += part.getCurrentLoad();
}
if(totalLoad==source.getFileLength()){
return true;
}
else
return false;
}
public void merger(Source source) throws IOException{
ArrayList<Part> parts=source.getParts();
RandomAccessFile ran=new RandomAccessFile(source.getSavePath()+File.separator+source.getFileName(),"rw");
for(Part part : parts){
File file=new File(source.getSavePath()+File.separator+part.getPartName());
InputStream is=new FileInputStream(file);
byte [] buffer=new byte[32];
int hasRead=0;
while((hasRead=is.read())!=-1){
ran.write(buffer,0,hasRead);
}
is.close();
}
ran.close();
}
}
at index.download.StartDownload.startLoad(StartDownload.java:24)
at index.NewTaskFrame$1.actionPerformed(NewTaskFrame.java:93)都把行号给些出来了对应你哪两行阿?
感觉source 或者source.getParts() 是 null,怀疑 url,path,等没设置对。
import java.net.URLConnection;
import java.util.ArrayList;public class Source {
private String urlAddress;
private String savePath;
private String fileName;
private ArrayList<Part> parts;
这个ArrayList<Part> parts 没有初始化
鉴定完毕
private ArrayList<Part> parts;没有初始化并且没有set方法。getParts()方法永远返回null.