編輯:Android開發實例
最近在做一個項目涉及到將包含圖片的簡單網頁下載到本地,方便離線時觀看,在這裡分享一下,大家做下簡單修改就可以用到自己的項目中了。(這裡用到了AQuery庫)
代碼如下:
package com.nekocode.xuedao.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.xuedao.PublicData;
import com.nekocode.xuedao.PublicData.Subscribe;
public class HtmlStorageHelper {
private String URL = "http://eduproject.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;
}
}
當開發基於軟件模式的游戲時,通過縮放視頻緩沖區來適應顯示尺寸是最棘手的問題之一。當面對眾多不同的分辨率時(比如開放環境下的Android),該問題會變得更加麻煩,
JSON代表JavaScript對象符號。它是一個獨立的數據交換格式,是XML的最佳替代品。本章介紹了如何解析JSON文件,並從中提取所需的信息。Android提供了四個
JSON代表JavaScript對象符號。它是一個獨立的數據交換格式,是XML的最佳替代品。本章介紹了如何解析JSON文件,並從中提取所需的信息。Android提供了四個
Android應用程序可以在許多不同地區的許多設備上運行。為了使應用程序更具交互性,應用程序應該處理以適合應用程序將要使用的語言環境方面的文字,數字,文件等。在本章中,我