求解。
代码如下，作业要求是做一个能在读取时显示进度条的程序。用PROGRESSMONITORINPUTSTREAM类解决。
import java.awt.TextArea;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import javax.swing.JFrame;
import javax.swing.ProgressMonitorInputStream;
public class ProIO extends JFrame{
public static final long serialVersionUID=1L;
TextArea ta=new TextArea();
public ProIO(){
setBounds(200,200,500,500);
setVisible(true);
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
getContentPane();
add(ta);
}
public static void main(String[] args) throws IOException {
ProIO proio=new ProIO();
File file=new File("D:/test.txt");
try{
FileInputStream in=new FileInputStream(file);
ProgressMonitorInputStream pmi=new ProgressMonitorInputStream(proio, "读取中", in);
byte[] read1=new byte[1024];
while(pmi.read(read1)!=-1){
proio.ta.append(read1.toString());
}
pmi.close();
}catch(FileNotFoundException e){
System.out.println("错误！文件未找到");
}
}
}