Android开发（13）-- 互联网访问图片，在android客户端显示

最新推荐文章于 2024-10-22 11:37:27 发布

转载最新推荐文章于 2024-10-22 11:37:27 发布 · 435 阅读

本文详细介绍了Android应用中布局界面的实现方法，并通过Java代码展示了如何进行URL的封装和网络请求，包括GET方式的请求及图片的获取。同时，提供了一个检查网络连接状态的封装类，以及输出流的封装类，帮助开发者更好地处理网络请求和数据传输。

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1、布局界面

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<RelativeLayoutxmlns: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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity">
<EditText
android:id="@+id/url_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:ems="10"
android:inputType="textPostalAddress"
android:text="@string/url_text">
<requestFocus />
</EditText>
<Button
android:id="@+id/btn_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/url_text"
android:layout_below="@+id/url_text"
android:layout_marginTop="32dp"
android:onClick="sendHttp"
android:text="@string/btn_text"/>
<ImageView
android:id="@+id/iv_ie"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignRight="@+id/url_text"
android:layout_below="@+id/btn_text"
android:src="@drawable/ic_launcher"/>
</RelativeLayout>

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<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<EditText
android:id="@+id/url_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:ems="10"
android:inputType="textPostalAddress"
android:text="@string/url_text" >
<requestFocus />
</EditText>
<Button
android:id="@+id/btn_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/url_text"
android:layout_below="@+id/url_text"
android:layout_marginTop="32dp"
android:onClick="sendHttp"
android:text="@string/btn_text" />
<ImageView
android:id="@+id/iv_ie"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignRight="@+id/url_text"
android:layout_below="@+id/btn_text"
android:src="@drawable/ic_launcher" />
</RelativeLayout>

2、封转的一些类

URL的封装：

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package com.example.lession08_code.utis;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
public class HttpUtils {
public static String sendGet(String path){
String content=null;
try{
//设置访问的url
URL url=new URL(path);
//打开请求
HttpURLConnection httpURLConnection=(HttpURLConnection) url.openConnection();
//设置请求的信息
httpURLConnection.setRequestMethod("GET");
//设置请求是否超时
httpURLConnection.setConnectTimeout(5000);
//判断服务器是否响应成功
if(httpURLConnection.getResponseCode()==200){
//获取响应的输入流对象
InputStream is=httpURLConnection.getInputStream();
byte data[]=StreamTools.isTodata(is);
//把转换成字符串
content=new String(data);
//内容编码方式
if(content.contains("gb2312")){
content=new String(data,"gb2312");
}
}
//断开连接
httpURLConnection.disconnect();
}catch(Exception e){
e.printStackTrace();
}
return content;
}
public static Bitmap sendGets(String path){
Bitmap bitmap=null;
try{
//设置访问的url
URL url=new URL(path);
//打开请求
HttpURLConnection httpURLConnection=(HttpURLConnection) url.openConnection();
//设置请求的信息
httpURLConnection.setRequestMethod("GET");
//设置请求是否超时
httpURLConnection.setConnectTimeout(5000);
//判断服务器是否响应成功
if(httpURLConnection.getResponseCode()==200){
//获取响应的输入流对象
InputStream is=httpURLConnection.getInputStream();
//直接把is的流转换成Bitmap对象
bitmap=BitmapFactory.decodeStream(is);
}
//断开连接
httpURLConnection.disconnect();
}catch(Exception e){
e.printStackTrace();
}
return bitmap;
}
}

[java] view plain copy

package com.example.lession08_code.utis;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
public class HttpUtils {
public static String sendGet(String path){
String content=null;
try{
//设置访问的url
URL url=new URL(path);
//打开请求
HttpURLConnection httpURLConnection=(HttpURLConnection) url.openConnection();
//设置请求的信息
httpURLConnection.setRequestMethod("GET");
//设置请求是否超时
httpURLConnection.setConnectTimeout(5000);
//判断服务器是否响应成功
if(httpURLConnection.getResponseCode()==200){
//获取响应的输入流对象
InputStream is=httpURLConnection.getInputStream();
byte data[]=StreamTools.isTodata(is);
//把转换成字符串
content=new String(data);
//内容编码方式
if(content.contains("gb2312")){
content=new String(data,"gb2312");
}
}
//断开连接
httpURLConnection.disconnect();
}catch(Exception e){
e.printStackTrace();
}
return content;
}
public static Bitmap sendGets(String path){
Bitmap bitmap=null;
try{
//设置访问的url
URL url=new URL(path);
//打开请求
HttpURLConnection httpURLConnection=(HttpURLConnection) url.openConnection();
//设置请求的信息
httpURLConnection.setRequestMethod("GET");
//设置请求是否超时
httpURLConnection.setConnectTimeout(5000);
//判断服务器是否响应成功
if(httpURLConnection.getResponseCode()==200){
//获取响应的输入流对象
InputStream is=httpURLConnection.getInputStream();
//直接把is的流转换成Bitmap对象
bitmap=BitmapFactory.decodeStream(is);
}
//断开连接
httpURLConnection.disconnect();
}catch(Exception e){
e.printStackTrace();
}
return bitmap;
}
}

判断网络是否连接的封装类

[java] view plain copy

package com.example.lession08_code.utis;
import android.app.AlertDialog;
import android.content.ComponentName;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.widget.Toast;
public class NetWorkUtils {
private Context context;
// 网路链接管理对象
public ConnectivityManager connectivityManager;
public NetWorkUtils(Context context) {
this.context = context;
// 获取网络链接的对象
connectivityManager = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
}
public boolean setActiveNetWork() {
boolean flag=false;
// 获取可用的网络链接对象
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if (networkInfo == null) {
new AlertDialog.Builder(context)
.setTitle("网络不可用")
.setMessage("可以设置网络?")
.setPositiveButton("确认",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
Toast.makeText(context, "点击确认",
Toast.LENGTH_LONG).show();
// 声明意图
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MAIN);
intent.addCategory("android.intent.category.LAUNCHER");
intent.setComponent(new ComponentName(
"com.android.settings",
"com.android.settings.Settings"));
intent.setFlags(0x10200000);
// 执行意图
context.startActivity(intent);
}
})
.setNegativeButton("取消",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
}
}).show();// 必须.show();
}
if(networkInfo!=null){
flag=true;
}
return flag;
}
}

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package com.example.lession08_code.utis;
import android.app.AlertDialog;
import android.content.ComponentName;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.widget.Toast;
public class NetWorkUtils {
private Context context;
// 网路链接管理对象
public ConnectivityManager connectivityManager;
public NetWorkUtils(Context context) {
this.context = context;
// 获取网络链接的对象
connectivityManager = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
}
public boolean setActiveNetWork() {
boolean flag=false;
// 获取可用的网络链接对象
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if (networkInfo == null) {
new AlertDialog.Builder(context)
.setTitle("网络不可用")
.setMessage("可以设置网络?")
.setPositiveButton("确认",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
Toast.makeText(context, "点击确认",
Toast.LENGTH_LONG).show();
// 声明意图
Intent intent = new Intent();
intent.setAction(Intent.ACTION_MAIN);
intent.addCategory("android.intent.category.LAUNCHER");
intent.setComponent(new ComponentName(
"com.android.settings",
"com.android.settings.Settings"));
intent.setFlags(0x10200000);
// 执行意图
context.startActivity(intent);
}
})
.setNegativeButton("取消",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
}
}).show();// 必须.show();
}
if(networkInfo!=null){
flag=true;
}
return flag;
}
}

输出流的封装类

[java] view plain copy

package com.example.lession08_code.utis;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
public class StreamTools {
public staticbyte[] isTodata(InputStream is) throws IOException{
//字节输出流
ByteArrayOutputStream bops=new ByteArrayOutputStream();
//读取数据的缓冲区
byte buffer[]=newbyte[1024];
//读取记录的长度
int len=0;
while((len=is.read(buffer))!=-1){
bops.write(buffer, 0, len);
}
//把读取的内容转换成byte数组
byte data[]=bops.toByteArray();
return data;
}
}

[java] view plain copy

package com.example.lession08_code.utis;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
public class StreamTools {
public static byte[] isTodata(InputStream is) throws IOException{
//字节输出流
ByteArrayOutputStream bops=new ByteArrayOutputStream();
//读取数据的缓冲区
byte buffer[]=new byte[1024];
//读取记录的长度
int len=0;
while((len=is.read(buffer))!=-1){
bops.write(buffer, 0, len);
}
//把读取的内容转换成byte数组
byte data[]=bops.toByteArray();
return data;
}
}

注意：在这里还需要加权限问题

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<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>

[java] view plain copy

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>