java文件读取
1 package textopen;
2
3 import java.awt.BorderLayout;
4 import java.awt.EventQueue;
5 import java.awt.event.ActionEvent;
6 import java.awt.event.ActionListener;
7 import java.io.File;
8 import java.io.FileInputStream;
9 import java.io.FileNotFoundException;
10 import java.io.IOException;
11
12 import javax.swing.JFrame;
13 import javax.swing.JPanel;
14 import javax.swing.border.EmptyBorder;
15 import javax.swing.JButton;
16 import java.awt.CardLayout;
17 import javax.swing.JTextField;
18 import javax.swing.JScrollPane;
19 import javax.swing.JTextArea;
20 import java.awt.GridLayout;
21
22 public class textopen1 extends JFrame implements ActionListener{
23
24 private JPanel contentPane;
25 private JButton openButton;
26 private JPanel panel;
27 private Object i;
28 private JScrollPane scrollPane;
29 private JPanel panel_1;
30 private JTextArea text;
31
32 /**
33 * Launch the application.
34 */
35 public static void main(String[] args) {
36 EventQueue.invokeLater(new Runnable() {
37 public void run() {
38 try {
39 textopen1 frame = new textopen1();
40 frame.setVisible(true);
41 } catch (Exception e) {
42 e.printStackTrace();
43 }
44 }
45 });
46 }
47
48 /**
49 * Create the frame.
50 */
51 public textopen1() {
52 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
53 setBounds(100, 100, 595, 523);
54 contentPane = new JPanel();
55 contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
56 contentPane.setLayout(new BorderLayout(0, 0));
57 setContentPane(contentPane);
58
59 panel = new JPanel();
60 contentPane.add(panel, BorderLayout.SOUTH);
61
62 openButton = new JButton("\u786E\u5B9A");
63 openButton.addActionListener(this);
64 panel.add(openButton);
65
66 scrollPane = new JScrollPane();
67 contentPane.add(scrollPane, BorderLayout.CENTER);
68
69 panel_1 = new JPanel();
70 scrollPane.setViewportView(panel_1);
71 panel_1.setLayout(new CardLayout(0, 0));
72
73 text = new JTextArea();
74 panel_1.add(text, "name_30136914873902");
75
76
77 }
78 public static void open(){
79 FileInputStream fis=null;
80 int i=0;
81 try {
82 fis=new FileInputStream("F:/java资源/java中线程.txt");
83 } catch (FileNotFoundException e1) {
84 // TODO 自动生成的 catch 块
85 e1.printStackTrace();
86 }
87 // System.out.println(fis);
88 try {
89
90 fis.read();
91 } catch (IOException e1) {
92 // TODO 自动生成的 catch 块
93 e1.printStackTrace();
94 }
95
96 //当i=-1时，文件到达文件尾部
97 while(i !=-1){
98 try {
99 i=fis.read();
100 } catch (IOException e1) {
101 // TODO 自动生成的 catch 块
102 e1.printStackTrace();
103 }
104 }
105 }
106
107 public void input() throws Exception
108 {
109 File file = new File("F:/java资源/java中线程.txt");//读取文件
110 FileInputStream fi = new FileInputStream(file);//创建字节流，打开该 文件
111 byte[] b = new byte[fi.available()];//fi.available 可以获取文件占多少字节
112 int a = -1;
113 while((a= fi.read(b))!= -1)//判断文件是否到达文件末尾
114 {
115 //System.out.println(new String(b));
116 }
117 // System.out.println(new String(b));
118 text.setText(new String(b));
119 //关闭流
120 fi.close();
121 }
122 @Override
123 public void actionPerformed(ActionEvent e) {
124 // TODO 自动生成的方法存根
125 if(e.getSource()==openButton){
126 try {
127 input();
128 } catch (Exception e1) {
129 // TODO 自动生成的 catch 块
130 e1.printStackTrace();
131 }
132 }
133 }
134 }
单击读取文件按钮的运行的结果
