这是代码：
private EditText userText;
private Button bsend;
private TextView chatwindow;
private Socket connection;
private ObjectOutputStream output;
private ObjectInputStream input;
private String serverIP="10.0.2.2";
private String message="";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
userText = (EditText) findViewById(R.id.userText);
userText.setEnabled(false);
chatwindow=(TextView) findViewById(R.id.chatwindow);
bsend = (Button) findViewById(R.id.bsend);
startRunning();
bsend.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
sendMessage(userText.getText().toString());
userText.setText("");
}
}
);
}
public void startRunning(){
try{
connectToServer();
setupStreams();
chatUp();
}
catch(EOFException e){
showMessage("\nServer Closed The Connection\n");
} catch (IOException e) {
e.printStackTrace();
}finally {
closeSystems();
}
}
public void connectToServer()throws IOException{
showMessage("\n********Connecting to Server......*********\n");
connection = new Socket(InetAddress.getByName(serverIP),5000);
showMessage("\n********Connection Successful*********\n");
}
public void setupStreams() throws IOException{
output = new ObjectOutputStream(connection.getOutputStream());
output.flush();
input = new ObjectInputStream(connection.getInputStream());
showMessage("\n***********Streams Setup Successfully***************\n");
}
public void chatUp() throws IOException{
ableToType(true);
showMessage("\nChatting can now Begin......\n");
do{
try {
message = (String) input.readObject();
sendMessage("\n"+message);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
while(!message.equals("SERVER - END"));
}
public void closeSystems() {
ableToType(false);
try{
output.close();
input.close();
connection.close();
}
catch(IOException e){
e.printStackTrace();
}
}
public void sendMessage(final String m){
try{
output.writeObject(m);
output.flush();
}
catch(IOException e){
e.printStackTrace();
}
}
public void showMessage(final String m){
chatwindow.append(m);
}
public void ableToType(final boolean tof){
userText.setEnabled(tof);
}
尝试使用ip 10.0.2.2将仿真器连接到计算机。 这只发生在android系统上。我在eclipse中测试了类似的代码并没有问题。 欣赏它，如果有人能告诉我为什么我在output.close（）得到Null指针异常 感谢