android 之HttpURLConnection的post,get方式请求数据
get方式和post方式的区别：
1.请求的URL地址不同：
post："http://xx:8081//servlet/LoginServlet"
get：http://xxx:8081//servlet/LoginServlet?username=root&pwd=123
2.请求头不同：
****post方式多了几个请求头：Content-Length , Cache-Control , Origin
openConnection.setRequestProperty("Content-Length", body.length()+"");
openConnection.setRequestProperty("Cache-Control", "max-age=0");
openConnection.setRequestProperty("Origin", "http://xx:8081");
****post方式还多了请求的内容：username=root&pwd=123
//设置UrlConnection可以写请求的内容
openConnection.setDoOutput(true);
//获取一个outputstream，并将内容写入该流
openConnection.getOutputStream().write(body.getBytes());
3.请求时携带的内容大小不同
get:1k
post:理论无限制
登录的布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.yb.myapplication.MainActivity">
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/input_username"
android:hint="@string/input_username"/>
<EditText
android:layout_marginTop="10dp"
android:layout_marginBottom="10dp"
android:inputType="textPassword"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/input_password"
android:hint="@string/input_password"/>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<CheckBox
android:layout_marginLeft="30dp"
android:layout_centerVertical="true"
android:layout_alignParentLeft="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/cb_rem"
android:text="@string/reme_password"/>
<Button
android:layout_marginRight="30dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:layout_alignParentRight="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/bt_login"
android:text="@string/bt_login"/>
</RelativeLayout>
</LinearLayout>
登录的Activity代码
public class GetPostActivity extends AppCompatActivity {
private EditText et_username;
private EditText et_password;
private CheckBox cb_rem;
private Button bt_login;
private Context mcontext;
private String username;
private String password;
private boolean isRem;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_get_post);
et_username = (EditText) findViewById(R.id.input_username);
et_password = (EditText) findViewById(R.id.input_password);
cb_rem = (CheckBox) findViewById(R.id.cb_rem);
bt_login = (Button) findViewById(R.id.bt_login);
bt_login.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
login();
}
});
}
//创建一个handler
Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
boolean isloginsuccess = (boolean) msg.obj;
if (isloginsuccess) {
//判断是否记住密码,要保存到本地，封装成方法
if (isRem) {
//保存用户名和密码
boolean result = UserInfoUtil.saveUserInfo(mcontext, username, password);
if (result) {
Toast.makeText(getApplicationContext(), "用户名和密码保存成功", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "用户名和密码保存失败", Toast.LENGTH_SHORT).show();
}
} else {
Toast.makeText(getApplicationContext(), "登录成功", Toast.LENGTH_SHORT).show();
}
} else {
Toast.makeText(getApplicationContext(), "登录失败", Toast.LENGTH_SHORT).show();
}
}
};
public void login() {
username = et_username.getText().toString().trim();
password = et_password.getText().toString().trim();
isRem = cb_rem.isChecked();
//判断是否密码或者用户名为空
if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
Toast.makeText(this, "用户名和密码不能为空", Toast.LENGTH_SHORT).show();
return;
}
//post方法登录是否成功
LoginHttpUtil.requestNetForGetLogin(handler, username, password);
}
}
新建一个Net包，处理网络请求的操作，新建一个loginhttputil.java
public class LoginHttpUtil {
//get方式登录
public static void requestNetForGetLogin(final Handler handler,final String username,final String password) {
//在子线程中操作网络请求
new Thread(new Runnable() {
@Override
public void run() {
//urlConnection请求服务器，验证
try {
//1：url对象
URL url = new URL("http://192.168.1.100:8081//servlet/LoginServlet?username=" + URLEncoder.encode(username)+ "&pwd=" + URLEncoder.encode(password) + "");
//2;url.openconnection
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//3
conn.setRequestMethod("GET");
conn.setConnectTimeout(10 * 1000);
//4
int code = conn.getResponseCode();
if (code == 200) {
InputStream inputStream = conn.getInputStream();
String result = StreamUtil.stremToString(inputStream);
System.out.println("=====================服务器返回的信息：：" + result);
boolean isLoginsuccess=false;
if (result.contains("success")) {
isLoginsuccess=true;
}
Message msg = Message.obtain();
msg.obj=isLoginsuccess;
handler.sendMessage(msg);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
}
//post方式登录
public static void requestNetForPOSTLogin(final Handler handler,final String username,final String password) {
new Thread(new Runnable() {
@Override
public void run() {
//urlConnection请求服务器，验证
try {
//1：url对象
URL url = new URL("http://192.168.1.100:8081//servlet/LoginServlet");
//2;url.openconnection
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//3设置请求参数
conn.setRequestMethod("POST");
conn.setConnectTimeout(10 * 1000);
//请求头的信息
String body = "username=" + URLEncoder.encode(username) + "&pwd=" + URLEncoder.encode(password);
conn.setRequestProperty("Content-Length", String.valueOf(body.length()));
conn.setRequestProperty("Cache-Control", "max-age=0");
conn.setRequestProperty("Origin", "http://192.168.1.100:8081");
//设置conn可以写请求的内容
conn.setDoOutput(true);
conn.getOutputStream().write(body.getBytes());
//4响应码
int code = conn.getResponseCode();
if (code == 200) {
InputStream inputStream = conn.getInputStream();
String result = StreamUtil.stremToString(inputStream);
System.out.println("=====================服务器返回的信息：：" + result);
boolean isLoginsuccess=false;
if (result.contains("success")) {
isLoginsuccess=true;
}
Message msg = Message.obtain();
msg.obj=isLoginsuccess;
handler.sendMessage(msg);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
}
}
二：get方式提交数据时候出现乱码的情况l;解决办法如下：
一般在开发客户端和服务端的编码要保持一致。
android端的默认编码是utf-8;
做url请求时需要对参数进行URLEncode编码.
URL url = new URL("http://xx:8081/servlet/LoginServlet?username="+URLEncoder.encode(username)+"&pwd="+URLEncoder.encode(password))
# 2. post方式提交数据乱码解决
String body = "username=" + URLEncoder.encode(username) + "&pwd=" + URLEncoder.encode(password);
