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import java.io.*;
import java.net.*;
import java.sql.*;
class ser1 implements Runnable{
ServerSocket ss;
Socket sc;
DataInputStream in=null;
DataOutputStream out=null;
InputStream in_data;
OutputStream out_data;
String str;
public ser1() {
try{
ss=new ServerSocket(1234);
while(true){
sc=ss.accept();
Thread m=new Thread(this);
m.start();
}
}
catch(IOException ee){
System.out.println("错误");
}
}
public void run() {
try{
while(true){
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
in=new DataInputStream(in_data);
out=new DataOutputStream(out_data);
str=in.readUTF();
out.writeUTF(str);
if(str.equals("end")){
in.close();
out.close();
sc.close();
}
}
}
catch(IOException e){
System.out.println("输入输出流错误");
}
}
}
class ser2 implements Runnable{
ServerSocket ss;
Socket sc;
DataInputStream in=null;
DataOutputStream out=null;
InputStream in_data;
OutputStream out_data;
String str;
String driver="sun.jdbc.odbc.JdbcOdbcDriver";
static String db="D:\\Java\\JavaWork\\NWIND.MDB";
String url1="jdbc:odbc:NWIND";
Connection conn=null;
Statement stmt=null;
PreparedStatement ps=null;
ResultSet rs=null;
String user="";
String pwd="";
String a="select * from 学生 where 姓名=";
String s1;
String s2;
public void connect()throws SQLException {
try {
Class.forName(driver);
conn = DriverManager.getConnection(url1,user,pwd);
stmt = conn.createStatement();
rs=stmt.executeQuery(a+str);
while (rs.next()){
s1=rs.getString(1);
s2=rs.getString(2);
}
}catch (Exception e){
System.out.println(e);
}finally{
stmt.close();
conn.close();
}
}
public ser2() {
try{
ss=new ServerSocket(1234);
while(true){
sc=ss.accept();
Thread m=new Thread(this);
m.start();
}
}
catch(IOException ee){
System.out.println("错误");
}
}
public void run() {
try{
while(true){
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
in=new DataInputStream(in_data);
out=new DataOutputStream(out_data);
str=in.readUTF();
String[] ary = str.split(" ");
while(str.equals("end"))
if(ary[0].equals(s1)){
if(ary[2].equals(s2)){
new ser1();
out.writeUTF("密码正确");
break;
}
else if(ary[2]!=s2){
out.writeUTF("密码错误");
}
}
in.close();
out.close();
sc.close();
}
}
catch(IOException e){
System.out.println("输入输出流错误");
}
}
}
class ser{
public static void main(String[] args){
new ser2();
}
}
结果是：
错误
import java.net.*;
import java.sql.*;
class ser1 implements Runnable{
ServerSocket ss;
Socket sc;
DataInputStream in=null;
DataOutputStream out=null;
InputStream in_data;
OutputStream out_data;
String str;
public ser1() {
try{
ss=new ServerSocket(1234);
while(true){
sc=ss.accept();
Thread m=new Thread(this);
m.start();
}
}
catch(IOException ee){
System.out.println("错误");
}
}
public void run() {
try{
while(true){
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
in=new DataInputStream(in_data);
out=new DataOutputStream(out_data);
str=in.readUTF();
out.writeUTF(str);
if(str.equals("end")){
in.close();
out.close();
sc.close();
}
}
}
catch(IOException e){
System.out.println("输入输出流错误");
}
}
}
class ser2 implements Runnable{
ServerSocket ss;
Socket sc;
DataInputStream in=null;
DataOutputStream out=null;
InputStream in_data;
OutputStream out_data;
String str;
String driver="sun.jdbc.odbc.JdbcOdbcDriver";
static String db="D:\\Java\\JavaWork\\NWIND.MDB";
String url1="jdbc:odbc:NWIND";
Connection conn=null;
Statement stmt=null;
PreparedStatement ps=null;
ResultSet rs=null;
String user="";
String pwd="";
String a="select * from 学生 where 姓名=";
String s1;
String s2;
public void connect()throws SQLException {
try {
Class.forName(driver);
conn = DriverManager.getConnection(url1,user,pwd);
stmt = conn.createStatement();
rs=stmt.executeQuery(a+str);
while (rs.next()){
s1=rs.getString(1);
s2=rs.getString(2);
}
}catch (Exception e){
System.out.println(e);
}finally{
stmt.close();
conn.close();
}
}
public ser2() {
try{
ss=new ServerSocket(1234);
while(true){
sc=ss.accept();
Thread m=new Thread(this);
m.start();
}
}
catch(IOException ee){
System.out.println("错误");
}
}
public void run() {
try{
while(true){
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
in=new DataInputStream(in_data);
out=new DataOutputStream(out_data);
str=in.readUTF();
String[] ary = str.split(" ");
while(str.equals("end"))
if(ary[0].equals(s1)){
if(ary[2].equals(s2)){
new ser1();
out.writeUTF("密码正确");
break;
}
else if(ary[2]!=s2){
out.writeUTF("密码错误");
}
}
in.close();
out.close();
sc.close();
}
}
catch(IOException e){
System.out.println("输入输出流错误");
}
}
}
class ser{
public static void main(String[] args){
new ser2();
}
}
结果是：
错误
...全文
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笑莫问 2012-12-26
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错误，真有意思。。。嘿嘿
isbn888 2012-12-26
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xiaozhu1991 2012-12-25
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Test1.actionPerformed(Test.java:77)
应该是test.java里面的代码new test1();有问题，也就是test1类的构造函数有空指针问题
不可笑的小丑 2012-12-25
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求大神，能改的话帮我多改下，分数我还会追加的，急急急！！！
失落夏天 2012-12-25
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catch(IOException ee){
System.out.println("错误");
}
这里最好还是改成
e.printStackTrace();比较合适。
另外：java.lang.NullPointerException
空指针异常
很明显啊，你有一个对象未实例化或者忘了给某个变量赋值了。
不可笑的小丑 2012-12-25
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服务器端程序：
import java.io.*;
import java.net.*;
import java.sql.*;
class ser1 implements Runnable{
ServerSocket ss;
Socket sc;
DataInputStream in=null;
DataOutputStream out=null;
InputStream in_data;
OutputStream out_data;
String str;
public ser1() {
try{
ss=new ServerSocket(1234);
while(true){
sc=ss.accept();
Thread m=new Thread(this);
m.start();
}
}
catch(IOException ee){
System.out.println("错误");
}
}
public void run() {
try{
while(true){
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
in=new DataInputStream(in_data);
out=new DataOutputStream(out_data);
str=in.readUTF();
out.writeUTF(str);
if(str.equals("end")){
in.close();
out.close();
sc.close();
}
}
}
catch(IOException e){
System.out.println("输入输出流错误");
}
}
}
class ser2 implements Runnable{
ServerSocket ss;
Socket sc;
DataInputStream in=null;
DataOutputStream out=null;
InputStream in_data;
OutputStream out_data;
String str;
String driver="sun.jdbc.odbc.JdbcOdbcDriver";
static String db="D:\\Java\\JavaWork\\NWIND.MDB";
String url1="jdbc:odbc:NWIND";
Connection conn=null;
Statement stmt=null;
PreparedStatement ps=null;
ResultSet rs=null;
String user="";
String pwd="";
String a="select * from 学生 where 姓名=";
String s1;
String s2;
public ser2() {
try{
ss=new ServerSocket(1234);
while(true){
sc=ss.accept();
}
}
catch(IOException ee){
ee.printStackTrace();
System.out.println("错误");
}
}
public void run() {
try{
while(true){
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
in=new DataInputStream(in_data);
out=new DataOutputStream(out_data);
str=in.readUTF();
String[] ary = str.split(" ");
while(str.equals("end"))
if(ary[0].equals(s1)){
if(ary[2].equals(s2)){
new ser1();
out.writeUTF("密码正确");
break;
}
else if(ary[2]!=s2){
out.writeUTF("密码错误");
}
}
in.close();
out.close();
sc.close();
}
}
catch(IOException e){
System.out.println("输入输出流错误");
}
}
public void connect()throws SQLException {
try {
Class.forName(driver);
conn = DriverManager.getConnection(url1,user,pwd);
stmt = conn.createStatement();
rs=stmt.executeQuery(a+str);
while (rs.next()){
s1=rs.getString(1);
s2=rs.getString(2);
}
}catch (Exception e){
System.out.println(e);
}finally{
stmt.close();
conn.close();
}
}
}
class ser{
public static void main(String[] args){
new ser2();
}
}
客户端程序：
import java.awt.*;
import java.awt.event.*;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.swing.*;
class Test1 implements ActionListener
{
JFrame f;
Container cp;
JLabel m;
JTextField x;
JLabel n;
JTextField y;
JButton jb;
String a1;
String a2;
Socket s = null;
DataInputStream in=null;
DataOutputStream out=null;
Socket sc;
InputStream in_data;
OutputStream out_data;
String str;
int i=0;
public Test1()
{
f=new JFrame("lv");
cp=f.getContentPane();
m=new JLabel("请输入用户名");
x=new JTextField(10);
n=new JLabel(" 请输入密码");
y=new JTextField(10);
jb=new JButton("确定");
cp.setLayout(new FlowLayout());
cp.add(m);
cp.add(x);
cp.add(n);
cp.add(y);
cp.add(jb);
jb.addActionListener(this);
f.setSize(230, 200);
f.validate();
f.setVisible(true);
a1=x.getText();
a2=y.getText();
}
public void actionPerformed(ActionEvent e) {
try{
sc=new Socket("10.2.57.170",1234);
}catch(IOException e1){
System.out.println("找不到服务器");
}
try{
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
}catch(IOException e2){
System.out.println("建立输入输出流错误");
}
try{
str=in.readUTF();
out.writeUTF(a1+" "+a2);
out.flush();
if(str.equals("密码正确")){
out.writeUTF("end");
in.close();
out.close();
sc.close();
new Test2();
f.setVisible(false);
}
else if(str.equals("密码错误")){
JOptionPane.showMessageDialog(f,"密码错误");
}
}catch(IOException e3){
System.out.println("线路读写错误");
}
}
}
class Test2 implements ActionListener
{
public Test2(){
JFrame f=new JFrame("吕彬龙");
Container cp=f.getContentPane();
JLabel a=new JLabel("吕彬龙");
JButton a1=new JButton("聊天");
cp.setLayout(new FlowLayout());
cp.add(a);
cp.add(a1);
a1.addActionListener(this);
f.setSize(300,500);
f.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
new Test3();
}
}
class Test3 implements ActionListener
{
DataInputStream in=null;
DataOutputStream out=null;
Socket sc;
InputStream in_data;
OutputStream out_data;
String str;
String s1;
JTextArea text1;
JTextArea text2;
String text_2;
String text;
public Test3(){
text1=new JTextArea(20,50);
text2=new JTextArea(8,50);
JFrame f=new JFrame("聊天");
Container cp=f.getContentPane();
JScrollPane x=new JScrollPane(text1);
JButton jb=new JButton("发送");
cp.setLayout(new FlowLayout());
cp.add(x);
cp.add(text2);
cp.add(jb);
jb.addActionListener(this);
f.setSize(600,600);
f.setVisible(true);
f.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent we){
try{
out.writeUTF("end");
in.close();
out.close();
sc.close();
System.exit(0);
}catch(IOException e){
System.out.println("输入输出流错误");
}
}
});
while(true){
try{
s1=in.readUTF();
}catch(Exception ee){
System.out.println("接收错误");
}
Date dt = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss aa");
text=sdf.format(dt);
text1.setText(text1.getText()+text+"\n"+s1+"\n");
}
}
public void actionPerformed(ActionEvent e) {
try{
sc=new Socket("10.2.57.170",1234);
}catch(IOException e1){
System.out.println("找不到服务器");
}
try{
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
}catch(IOException e2){
System.out.println("建立输入输出流错误");
}
try{
out.writeUTF(text_2);
}catch(IOException e3){
System.out.println("线路读写错误");
}
Date dt = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss aa");
text=sdf.format(dt);
text_2=text2.getText();
text1.setText(text1.getText()+text+"\n"+text_2+"\n");
text2.setText(null);
}
}
class Test{
public static void main(String[] args)
{
new Test1();
}
}
错误是：
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Test1.actionPerformed(Test.java:77)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6297)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3275)
at java.awt.Component.processEvent(Component.java:6062)
at java.awt.Container.processEvent(Container.java:2039)
at java.awt.Component.dispatchEventImpl(Component.java:4660)
at java.awt.Container.dispatchEventImpl(Container.java:2097)
at java.awt.Component.dispatchEvent(Component.java:4488)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4575)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4236)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4166)
at java.awt.Container.dispatchEventImpl(Container.java:2083)
at java.awt.Window.dispatchEventImpl(Window.java:2489)
at java.awt.Component.dispatchEvent(Component.java:4488)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:668)
at java.awt.EventQueue.access$400(EventQueue.java:81)
at java.awt.EventQueue$2.run(EventQueue.java:627)
at java.awt.EventQueue$2.run(EventQueue.java:625)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$3.run(EventQueue.java:641)
at java.awt.EventQueue$3.run(EventQueue.java:639)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:638)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
不可笑的小丑 2012-12-25
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错误信息就是输出“错误”这两个字
nmyangym 2012-12-25
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类似的问题,在Test3里也存在。也要给in,out赋值。
snow-is-my-Love 2012-12-25
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求错误信息
MiceRice 2012-12-25
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把详细错误输出出来看看：
catch(IOException ee){
ee.printStackTrace(); // 增加这句话
System.out.println("错误");
}
估计很可能是端口已经被用过了。
nmyangym 2012-12-25
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public Test1()
{
f=new JFrame("lv");
cp=f.getContentPane();
m=new JLabel("请输入用户名");
x=new JTextField(10);
n=new JLabel(" 请输入密码");
y=new JTextField(10);
jb=new JButton("确定");
cp.setLayout(new FlowLayout());
cp.add(m);
cp.add(x);
cp.add(n);
cp.add(y);
cp.add(jb);
jb.addActionListener(this);
f.setSize(230, 200);
f.validate();
f.setVisible(true);
a1=x.getText();
a2=y.getText();
}
public void actionPerformed(ActionEvent e) {
try{
sc=new Socket("10.2.57.170",1234);
}catch(IOException e1){
System.out.println("找不到服务器");
}
try{
in_data=sc.getInputStream();
out_data=sc.getOutputStream();
//
//------------------加上两句试试
//
in=new DataInputStream(in_dta);
out= new DataOutputStream(out_data);
}catch(IOException e2){
System.out.println("建立输入输出流错误");
}
try{
str=in.readUTF();
out.writeUTF(a1+" "+a2);
out.flush();
if(str.equals("密码正确")){
out.writeUTF("end");
in.close();
out.close();
sc.close();
new Test2();
f.setVisible(false);
}
else if(str.equals("密码错误")){
JOptionPane.showMessageDialog(f,"密码错误");
}
}catch(IOException e3){
System.out.println("线路读写错误");
}
}
}
MiceRice 2012-12-25
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你请人帮忙改错误，至少自己大致得知道错误该怎么定位吧。。。
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Test1.actionPerformed(Test.java:77)
这个空指针，是在77行，你至少指出77行是哪行。。。然后再看看是什么东西没有初始化好啥的。
huage 2012-12-25
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out.writeUTF(a1+" "+a2);
out.flush();
这里有问题吧 out为空
