java 用文件对话框打开文件

//文件的打开import java.awt.FileDialog;import java.awt.event.*;import java.io.*;import java.io.File;import java.io.FileReader;public class FileOpen {private FileDialog filedialog_open;private String fileopen = null, filename = null;// 用于存放打开文件地址 和文件名private File file1; // 文件字节流对象private FileReader file_reader;//文件字符流对象private BufferedReader in;//文件行读取 写入对象private StringBuffer text = new StringBuffer();HaffmanFrame haffman= null;FileOpen(HaffmanFrame hf) {haffman = hf;filedialog_open = new FileDialog(haffman, "打开文件对话框", FileDialog.LOAD);// 打开文件对话框适配器filedialog_open.addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e) {filedialog_open.setVisible(false);}});}public void open() {String s = ""; filedialog_open.setVisible(true);fileopen = filedialog_open.getDirectory();// 返回文件对话框中显示的文件所属的目录filename = filedialog_open.getFile();// 返回当前文件对话框中显示的文件名的字符串表示// 如果不存在就返回NULLif (filename != null)// 判断打开的文件是否存在{try {file1 = new File(fileopen,filename );file_reader = new FileReader(file1); in = new BufferedReader(file_reader);//每次读取一行 while ((s = in.readLine()) != null) text.append(s + '/n'); in.close(); file_reader.close();} catch (IOException e2) {System.out.println("不能打开文件！");}}}//返回得到的文本字符串public String getText() {return new String(text);}}