Http的get和post请求简单应用

网络请求中需要遵循http协议，而http有许多方法，大家一般最常用的就是post和get请求方法了！

其中，post和get都可以向服务器发送和请求数据，而我们一般都习惯用get请求数据，post发送数据！get方法是把数据拼接到请求行里面，我们可以直接看到里面的数据，相比较post不安全，但是简单，快捷（大小限制不超过2K）！post则是把要发送的数据转换成流的方式，大小不限制，上传给服务器，相比较get安全些！

基础定义和知识讲解不详细，大家可以参考大神的讲解，详细学习：

链接地址

其中本人AS版本2.3.如果你的AS版本低于2.2估计运行我的代码会报错，因为用到了最新的ConstraintLayout书写的布局，学习ConstraintLayout的链接我也放上去：

constraintlayout学习

本DEMO地址

效果图上两张：





下面我们直接上代码：

Xml布局代码就不放了都是用鼠标拉过来拉过去自动生成的代码

MainActivity代码：

package com.btzh.myhttptest;

import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import CommonUntils.HttpUntils;

public class MainActivity extends BaseActivity implements View.OnClickListener {
private Button htmlbtn, picbtn,posthtmlbtn,postpichtn;
private TextView textView;
private ImageView imageView;
int viewID = -1;
HttpUntils Myuntils = new HttpUntils();
String XML_Url = "http://toutiao.sogou.com/?fr=qqxwtt";
String XMl_Url_test = "http://baike.sogou.com/v6234.htm?fromTitle=%E7%99%BE%E5%BA%A6";
String pic_Url = "http://d.ifengimg.com/mw978_mh598/p2.ifengimg.com/a/2017_15/65bdb6e5ca68409_size79_w930_h620.jpg";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
initViews();
}

/**
* 初始化视图控件
*/
private void initViews(){
htmlbtn = (Button) findViewById(R.id.button_gethtml);
htmlbtn.setOnClickListener(this);
picbtn = (Button) findViewById(R.id.button_getpic);
picbtn.setOnClickListener(this);
textView = (TextView)findViewById(R.id.textView);
imageView = (ImageView)findViewById(R.id.imageView);
posthtmlbtn = (Button)findViewById(R.id.button_posthtml);
posthtmlbtn.setOnClickListener(this);
postpichtn = (Button)findViewById(R.id.button_postpic);
postpichtn.setOnClickListener(this);
}

@Override
public void onClick(View v) {
viewID = v.getId();
if (viewID == R.id.button_gethtml)
{   //get获取XMl信息
new MyXMlTask().execute();

}else if (viewID == R.id.button_getpic)
{   //get获取图片信息
showProgressDialog("正在加载图片!");
new MyAsyncTask().execute();
}else if (viewID == R.id.button_posthtml)
{   //post获取xml信息
new MyPostTask().execute();
}else if (viewID == R.id.button_postpic)
{   //post获取图片信息
new MyPostpicTask().execute();
}else {

}
}

/**
* get方法获取图片信息
*/
private class MyAsyncTask extends AsyncTaskUntils<Object, Object, Object>{
@Override
protected void onPostExecute(Object o) {
super.onPostExecute(o);
hideProgressDialog();
if (textView.getVisibility()==View.VISIBLE){
textView.setText("");
textView.setVisibility(View.GONE);
}
imageView.setVisibility(View.VISIBLE);
imageView.setImageBitmap((Bitmap) o);
}
}

/**
* get 方法异步获取url数据
*/
private class MyXMlTask extends AsyncTask<String, Integer,String>{
@Override
protected void onPreExecute() {
super.onPreExecute();
showProgressDialog(R.string.XMl_Toast);
}

@Override
protected String doInBackground(String... params) {
String string = Myuntils.URL_getString(XML_Url);
return string;
}

@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
hideProgressDialog();
if (imageView.getVisibility()==View.VISIBLE){
imageView.setImageDrawable(null);
imageView.setVisibility(View.GONE);
}
textView.setVisibility(View.VISIBLE);
textView.setText(s);
}
}

/**
* Post 方法异步获取url数据
*/
private class MyPostTask extends AsyncTask<String,Integer,String>{
@Override
protected void onPreExecute() {
super.onPreExecute();
showProgressDialog("Post正在加载网页信息!");
}

@Override
protected String doInBackground(String... params) {
String postStr = Myuntils.URL_postString(XMl_Url_test);
return postStr;
}

@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
hideProgressDialog();
if (imageView.getVisibility()==View.VISIBLE){
imageView.setImageDrawable(null);
imageView.setVisibility(View.GONE);
}
textView.setVisibility(View.VISIBLE);
textView.setText(s);
}
}
/**
* Post 方法异步获取url图片数据
*/
private class MyPostpicTask extends AsyncTask<String,Object,Object>{
@Override
protected void onPreExecute() {
super.onPreExecute();
showProgressDialog("Post正在加载图片信息...");
}

@Override
protected Object doInBackground(String... params) {
Bitmap postbitmap = Myuntils.URL_postitmap(pic_Url);
return postbitmap;
}

@Override
protected void onPostExecute(Object o) {
super.onPostExecute(o);
hideProgressDialog();
if (textView.getVisibility()==View.VISIBLE){
textView.setText("");
textView.setVisibility(View.GONE);
}
imageView.setVisibility(View.VISIBLE);
imageView.setImageBitmap((Bitmap)o);
}
}
}

代码注释很详细，其中用的是asynctask异步来处理的消息，没有用handler,以后会用！

然后就是自己封装的http和流解析的两个类了，

package CommonUntils;

import android.graphics.Bitmap;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import CommonUntils.StreamTools;

/**
* Created by Lenovo on 2017/4/7.
*/

public class HttpUntils {
private int HTTP_TIMEOUT_CONNECTION = 6*10000;
private int HTTP_TIMER_READ = 1*10000;

/**
* 返回bitmap
* @param httpUrl
* @return
*/
public Bitmap URL_getbitmap(String httpUrl)
{
Bitmap bitmap = null;
if ("" == httpUrl||null==httpUrl){
return null;
}
InputStream inputStream = null;
try {
//创建url对象
URL url = new URL(httpUrl);
//打开connection连接
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
//设置请求方法
connection.setRequestMethod("GET");
//设置连接超时时间
connection.setConnectTimeout(HTTP_TIMEOUT_CONNECTION);
//设置读取时间
connection.setReadTimeout(HTTP_TIMER_READ);
//connection链接
connection.connect();
//判断是否连接成功，标识符号为200
if (HttpURLConnection.HTTP_OK!=connection.getResponseCode())
{
return null;
}
//获取请求到的流
inputStream = connection.getInputStream();
//bitmap接收流对象（流转换为Bitmap格式对象）
bitmap = StreamTools.getBitmap(inputStream);

} catch (IOException e) {
e.printStackTrace();
}finally {  //一般最好写上，用来关闭前面开启的流对象，来减少内存占用
try {
if (null!=inputStream){
inputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}

}
return bitmap;
}

public String URL_getString(String httpUrl)
{
String string = "";
if ("" == httpUrl || null==httpUrl){
return "值为空！";
}
InputStream inputStream = null;
try {
URL url = new URL(httpUrl);
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(HTTP_TIMEOUT_CONNECTION);
connection.setReadTimeout(HTTP_TIMER_READ);
connection.connect();
if (HttpURLConnection.HTTP_OK!=connection.getResponseCode())
{
return "连接失败！";
}
inputStream = connection.getInputStream();
string = StreamTools.getString(inputStream);

} catch (IOException e) {
e.printStackTrace();
}finally {
try {
if (null!=inputStream){
inputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}

}
return string;
}

/**
* post 请求数据返回 String
* @param httpUrl
* @return String
*/
public String URL_postString(String httpUrl)
{
if ("".equals(httpUrl) || null==httpUrl){
return null;
}
OutputStream outputStream = null;
String postStr = "";
InputStream inputStream = null;
try {
//创建Url对象
URL url = new URL(httpUrl);
//创建connection的url连接
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setConnectTimeout(HTTP_TIMEOUT_CONNECTION);
connection.setReadTimeout(HTTP_TIMER_READ);
connection.setRequestMethod("POST");
//这两个方法post必须开启
connection.setDoInput(true);
connection.setDoOutput(true);
connection.connect();
//这句话加上一直报错，说我已经connect成功服务器，是不是需要写在connection.connect();前面
//            connection.setUseCaches(false);
//data为需要传入服务器的数据，这里我们传空
String data = "";
//打开输入流
outputStream = connection.getOutputStream();
//往输入流中写入我们需要传入服务器的数据（格式为byte格式）
outputStream.write(data.getBytes());
outputStream.flush();
//判断是否响应成功（其实就是Tcp/IP三次握手是否成功）
if (HttpURLConnection.HTTP_OK!=connection.getResponseCode()){
return "连接失败";
}
//获取服务器返回数据流
inputStream = connection.getInputStream();
//转换为String格式
postStr = StreamTools.getString(inputStream);

} catch (IOException e) {
e.printStackTrace();
}finally {  //关闭各种流
try {
if (outputStream!=null){
outputStream.close();
}
if (inputStream!=null){
inputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}

}
return postStr;
}

/**
* post 请求数据返回Bitmap
* @param httpUrl
* @return Bitmap
*/
public Bitmap URL_postitmap(String httpUrl)
{
if ("".equals(httpUrl) || null==httpUrl){
return null;
}
OutputStream outputStream = null;
Bitmap postBitmap = null;
InputStream inputStream = null;
try {
URL url = new URL(httpUrl);
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setConnectTimeout(HTTP_TIMEOUT_CONNECTION);
connection.setReadTimeout(HTTP_TIMER_READ);
connection.setRequestMethod("POST");
connection.setDoInput(true);
connection.setDoOutput(true);
connection.connect();
//            connection.setUseCaches(false);
String data = "";
outputStream = connection.getOutputStream();
outputStream.write(data.getBytes());
outputStream.flush();
if (HttpURLConnection.HTTP_OK!=connection.getResponseCode()){
return null;
}
inputStream = connection.getInputStream();
postBitmap = StreamTools.getBitmap(inputStream);

} catch (IOException e) {
e.printStackTrace();
}finally {
try {
if (outputStream!=null){
outputStream.close();
}
if (inputStream!=null){
inputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return postBitmap;
}
}

Stream类

package CommonUntils;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

/**
* Created by Lenovo on 2017/4/7.
*/

public class StreamTools {
/**
* inputStream 转换 Bitmap;
* @param inputStream
* @return bitmap
*/
public static Bitmap getBitmap(InputStream inputStream){

if (null == inputStream){
return null;
}
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
return bitmap;
}

/**
* inputStream转String
* @param inputStream
* @return String
*/
public static String getString(InputStream inputStream){
if (null==inputStream){
return null;
}
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader reader = new BufferedReader(inputStreamReader);
StringBuffer stringBuffer = new StringBuffer("UTF-8");
String line = null;
try {
while ((line = reader.readLine())!=null){
stringBuffer.append(line+"\n");
}
} catch (IOException e) {
e.printStackTrace();
return null;
}
return stringBuffer.toString();
}

/**
* inputStream 转 byte[]
* @param inputStream
* @return byte[]
*/
public static byte[] getBytes(InputStream inputStream) {
String str = "";
byte[] readByte = new byte[1024];
int readCount = -1;
try {
while ((readCount = inputStream.read(readByte, 0, 1024)) != -1) {
str += new String(readByte).trim();
}
return str.getBytes();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}

/**
* inputStream 转 Drawable
* @param inputStream
* @return Drawable
*/
public static Drawable getDrawable(InputStream inputStream){
if (null==inputStream){
return null;
}
Bitmap bitmap = getBitmap(inputStream);
Drawable drawable = bitmap_Drawable(bitmap);
return drawable;
}
// Bitmap转换成Drawable
public static Drawable bitmap_Drawable(Bitmap bitmap) {
if (null==bitmap){
return null;
}
BitmapDrawable bd = new BitmapDrawable(bitmap);
Drawable drawable = (Drawable) bd;
return drawable;
}

}

可以直接调用类中方法即可！

最后Mainactivity 继承的是自己写的BaseActivity，用来控制进度条的显示，有兴趣可以下载demo进行测试！

下一篇要研究Handler和Thread的了，come on！ 有错误多谢大家指正！！！