html如何緩存圖片

⑴ android如何保存html文件,包括其中的圖片。

1、先示例圖片

2、操作代碼

package com.nekocode.xue.utils;

import java.io.File;

import java.io.FileOutputStream;

import java.util.ArrayList;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import android.content.ContentValues;

import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import com.androidquery.AQuery;

import com.androidquery.callback.AjaxCallback;

import com.androidquery.callback.AjaxStatus;

import com.nekocode.xue.PublicData;

import com.nekocode.xue.PublicData.Subscribe;

public class HtmlStorageHelper {

private String URL = "http://eproject.sinaapp.com/fetchurl.php/getcontent/";

private PublicData pd;

private AQuery aq;

private SQLiteDatabase mDB;

private String mDownloadPath;

public HtmlStorageHelper(Context context) {

pd = PublicData.getInstance();

aq = new AQuery(context);

mDB = context.openOrCreateDatabase("data.db", Context.MODE_PRIVATE, null);

mDB.execSQL("create table if not exists download_html(_id INTEGER PRIMARY KEY AUTOINCREMENT, content_id TEXT NOT NULL, title TEXT NOT NULL)");

mDownloadPath = pd.mAppPath + "download/";

File dir_file = new File(pd.mAppPath + "download/");

if(!dir_file.exists())

dir_file.mkdir();

}

public void saveHtml(final String id, final String title) {

if(isHtmlSaved(id))

return;

aq.ajax(URL+id, String.class, new AjaxCallback<String>() {

@Override

public void callback(String url, String html, AjaxStatus status) {

File dir_file = new File(mDownloadPath + id);

if(!dir_file.exists())

dir_file.mkdir();

Pattern pattern = Pattern.compile("(?<=src=")[^"]+(?=")");

Matcher matcher = pattern.matcher(html);

StringBuffer sb = new StringBuffer();

while(matcher.find()){

downloadPic(id, matcher.group(0));

matcher.appendReplacement(sb, formatPath(matcher.group(0)));

}

matcher.appendTail(sb);

html = sb.toString();

writeHtml(id, title, html);

}

});

}

private void downloadPic(String id, String url) {

File pic_file = new File(mDownloadPath + id + "/" + formatPath(url));

aq.download(url, pic_file, new AjaxCallback<File>() {

@Override

public void callback(String url, final File file, AjaxStatus status) {

}

});

}

private void writeHtml(String id, String title, String html) {

File html_file = new File(mDownloadPath + id + "/index.html");

FileOutputStream fos = null;

try {

fos=new FileOutputStream(html_file);

fos.write(html.getBytes());

} catch (Exception e) {

e.printStackTrace();

}finally{

try {

fos.close();

} catch (Exception e2) {

e2.printStackTrace();

}

}

ContentValues values = new ContentValues();

values.put("content_id", id);

values.put("title", title);

mDB.insert("download_html", "_id", values);

}

public boolean isHtmlSaved(String id) {

File file = new File(mDownloadPath + id);

if(file.exists()) {

file = new File(mDownloadPath + id + "/index.html");

if(file.exists())

return true;

}

deleteHtml(id);

return false;

}

public String getTitle(String id) {

Cursor c = mDB.rawQuery("select * from download_html where content_id=?", new String[]{id});

if(c.getCount() == 0)

return null;

c.moveToFirst();

int index1 = c.getColumnIndex("title");

return c.getString(index1);

}

public ArrayList<Subscribe> getHtmlList() {

Cursor c = mDB.rawQuery("select * from download_html", null);

ArrayList<Subscribe> list = new ArrayList<Subscribe>();

if(c.getCount() != 0) {

c.moveToFirst();

int index1 = c.getColumnIndex("content_id");

int index2 = c.getColumnIndex("title");

while (!c.isAfterLast()) {

String id = c.getString(index1);

if(isHtmlSaved(id)) {

Subscribe sub = new Subscribe(

id,

c.getString(index2),

Subscribe.FILE_DOWNLOADED

);

list.add(sub);

}

c.moveToNext();

}

}

return list;

}

public void deleteHtml(String id) {

mDB.delete("download_html", "content_id=?", new String[]{id});

File dir_file = new File(mDownloadPath + id);

deleteFile(dir_file);

}

private void deleteFile(File file) {

if (file.exists()) { // 判斷文件是否存在

if (file.isFile()) { // 判斷是否是文件

file.delete(); // delete()方法 你應該知道 是刪除的意思;

} else if (file.isDirectory()) { // 否則如果它是一個目錄

File files[] = file.listFiles(); // 聲明目錄下所有的文件 files[];

for (int i = 0; i < files.length; i++) { // 遍歷目錄下所有的文件

this.deleteFile(files[i]); // 把每個文件 用這個方法進行迭代

}

}

file.delete();

} else {

//

}

}

private String formatPath(String path) {

if (path != null && path.length() > 0) {

path = path.replace("\", "_");

path = path.replace("/", "_");

path = path.replace(":", "_");

path = path.replace("*", "_");

path = path.replace("?", "_");

path = path.replace(""", "_");

path = path.replace("<", "_");

path = path.replace("|", "_");

path = path.replace(">", "_");

}

return path;

}

}

3、這段代碼簡單修改就可以用到自己的項目中了