198.m1-lsitView显示subject的信息

操作的模式和app的显示类似，首先创建一个SubjectProtacal来请求服务器的json资源并解析，然后在SubjectFragment中通过ListView显示

由于HomeProtacal和SubjectProtacal请求中网络请求，保存在本地以及本地资源的加载都是类似的，解析不是类似的，因此现在将共性封装成BaseProtacal,在BaseProtacal.java中通过泛型来初始化相关的数据

同时，图片资源显示的BitmapUtils也是需要每次去创建，可以在BaseFragment中直接去创建避免在HomeFragment和SubjectFragment中重复创建，请求的数据的校检也在BaseFragment中实现，因为每一组数据的请求都会去校检

BaseFragment.java

package com.ldw.market.fragment; import java.util.List; import com.ldw.market.R; import com.ldw.market.domain.AppInfo; import com.ldw.market.manager.ThreadManager; import com.ldw.market.utils.BitmapHelper; import com.ldw.market.utils.ViewUtils; import com.lidroid.xutils.BitmapUtils; import android.os.Bundle; import android.os.SystemClock; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.FrameLayout; import android.widget.FrameLayout.LayoutParams; public abstract class BaseFragment extends Fragment { //初始化页面加载的5种状态 public static final int STATE_UNKOWN = 0; public static final int STATE_LOADING = 1; public static final int STATE_ERROR = 2; public static final int STATE_EMPTY = 3; public static final int STATE_SUCCESS = 4; public int state = STATE_UNKOWN; private View loadingView;// 加载中的界面 private View errorView;// 错误界面 private View emptyView;// 空界面 private View successView;// 加载成功的界面 private FrameLayout frameLayout; protected BitmapUtils bitmapUtils; //创建一个View对象 @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { bitmapUtils = BitmapHelper.getBitmapUtils(); if(frameLayout == null){ frameLayout = new FrameLayout(getActivity()); init(); // 在FrameLayout中 添加4种不同的界面：加载中, 加载错误,加载为空 ,加载成功 }else{ ViewUtils.removeParent(frameLayout); } //show();// 根据服务器的数据 切换状态 return frameLayout; } // 在FrameLayout中 添加4种不同的界面：加载中, 加载错误,加载为空 ,加载成功 private void init() { // 创建了加载中的界面 loadingView = createLoadingView(); if (loadingView != null) { frameLayout.addView(loadingView, new FrameLayout.LayoutParams( LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); } // 加载错误界面 errorView = createErrorView(); if (errorView != null) { frameLayout.addView(errorView, new FrameLayout.LayoutParams( LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); } // 加载空的界面 emptyView = createEmptyView(); if (emptyView != null) { frameLayout.addView(emptyView, new FrameLayout.LayoutParams( LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); } // 根据不同的状态显示不同的界面 showPage(); } //根据不同的状态显示不同的界面 private void showPage(){ //利用||,显示加载界面 if (loadingView != null) { loadingView.setVisibility(state == STATE_UNKOWN || state == STATE_LOADING ? View.VISIBLE : View.INVISIBLE); } //利用||,显示错误界面 if (errorView != null) { errorView.setVisibility(state == STATE_ERROR ? View.VISIBLE : View.INVISIBLE); } //利用||,显示空界面 if (emptyView != null) { emptyView.setVisibility(state == STATE_EMPTY ? View.VISIBLE : View.INVISIBLE); } if (state == STATE_SUCCESS) { //创建成功的时候加载成功页面 if (successView == null) { //为空的时候创建View successView = createSuccessView(); frameLayout.addView(successView, new FrameLayout.LayoutParams( LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); successView.setVisibility(View.VISIBLE); } }else{ //不成功的时候让页面隐藏 if(successView != null){ successView.setVisibility(View.INVISIBLE); } } } //加载成功的界面 public abstract View createSuccessView(); /* 创建加载中的界面 */ private View createErrorView() { View view = View.inflate(getActivity(), R.layout.loadpage_error, null); //点击按钮重新请求服务器更新界面 Button page_bt = (Button) view.findViewById(R.id.page_bt); page_bt.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { show(); } }); return view; } /* 加载错误界面 */ private View createEmptyView() { View view = View.inflate(getActivity(), R.layout.loadpage_empty, null); return view; } /* 加载空的界面 */ private View createLoadingView() { View view = View.inflate(getActivity(), R.layout.loadpage_loading, null); return view; } //更具服务器获取的状态显示界面 public void show() { //更新状态，当加载错误以后或者加载了空页面时候需要更新一下状态 if (state == STATE_ERROR || state == STATE_EMPTY) { state = STATE_LOADING; } // 请求服务器 获取服务器上数据 进行判断 // 请求服务器 返回一个结果 //子线程中请求服务器，同时休眠一下 //使用线程池管理 ThreadManager.getInstance().createLongPool().execute(new Runnable(){ @Override public void run() { //休眠2s SystemClock.sleep(2000); final LoadResult result = load(); //主线程刷新界面 getActivity().runOnUiThread(new Runnable() { @Override public void run() { if(result != null){ //更新状态 state = result.getValue(); //更新界面 showPage(); } } }); } }); showPage(); } //服务器返回的数据 protected abstract LoadResult load(); //服务器返回的枚举结果，来显示界面 public enum LoadResult{ error(2), empty(3), success(4); int value; //获取服务器返回的结果 LoadResult(int value) { this.value = value; } //获取到value public int getValue() { return value; } } //校验数据 public LoadResult checkData(List datas){ if(datas == null){ return LoadResult.error;//请求服务器数据失败 }else{ if(datas.size() == 0){ return LoadResult.empty; }else{ return LoadResult.success; } } } } BaseProtocol.java网络请求共性部分抽取出来，json数据的解析各个子类自己实现 package com.ldw.market.protocol; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.StringWriter; import com.ldw.market.http.HttpHelper; import com.ldw.market.http.HttpHelper.HttpResult; import com.ldw.market.utils.FileUtils; import com.lidroid.xutils.util.IOUtils; public abstract class BaseProtocol<T> { public T load(int index) { // 加载本地数据 String json = loadLocal(index); if (json == null) { // 请求服务器 json = loadServer(index); if (json != null) { saveLocal(json, index); } } if (json != null) { return parseJson(json); } else { return null; } } //从服务器请求json数据 private String loadServer(int index) { //请求地址http://127.0.0.1:8090/home?index=1 HttpResult httpResult = HttpHelper.get(HttpHelper.URL + getKey() + "?index=" + index); //得到结果 String json = httpResult.getString(); //System.out.println(json); return json; } //将json保存在本地:方法1把整个json文件写到一个本地文件中，方法2吧每条数据都摘出来保存在数据库中 private void saveLocal(String json, int index) { //创建一个buffer BufferedWriter bw = null; try { File dir=FileUtils.getCacheDir(); //创建一个文件 File file = new File(dir, getKey() + "_" + index); // /mnt/sdcard/market/cache/home_0 FileWriter fw = new FileWriter(file); bw = new BufferedWriter(fw); //在第一行写一个过期时间 bw.write(System.currentTimeMillis() + 1000 * 100 + ""); bw.newLine();// 换行 bw.write(json);// 把整个json文件保存起来 bw.flush(); bw.close(); } catch (Exception e) { e.printStackTrace(); }finally{ IOUtils.closeQuietly(bw); } } //加载本地保存的数据 private String loadLocal(int index) { // 如果发现时间过期了，就不用本地的缓存 File dir=FileUtils.getCacheDir();// 获取缓存所在的文件夹 //得到缓存文件 File file = new File(dir, getKey() + "_" + index); try { FileReader fr=new FileReader(file); BufferedReader br=new BufferedReader(fr); //获取过期时间 long outOfDate = Long.parseLong(br.readLine()); //判断是否过期， if(System.currentTimeMillis()>outOfDate){ return null; }else{ String str=null; StringWriter sw=new StringWriter(); while((str=br.readLine())!=null){ sw.write(str); } return sw.toString(); } } catch (Exception e) { e.printStackTrace(); return null; } } /** * 解析json * @param json * @return */ public abstract T parseJson(String json); /** * 说明了关键字home,subject.... */ public abstract String getKey(); }

SubjectBean.java这里是subject的bean

package com.ldw.market.domain; public class SubjectInfo { private String des; private String url; public String getDes() { return des; } public void setDes(String des) { this.des = des; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } @Override public String toString() { return "SubjectInfo [des=" + des + ", url=" + url + "]"; } public SubjectInfo() { super(); } public SubjectInfo(String des, String url) { super(); this.des = des; this.url = url; } } SubjectProtocol.java package com.ldw.market.protocol; import java.util.ArrayList; import java.util.List; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import com.ldw.market.domain.AppInfo; import com.ldw.market.domain.SubjectInfo; /* * SubjectProtocol网络请求 */ public class SubjectProtocol extends BaseProtocol <List<SubjectInfo>>{ @Override public List<SubjectInfo> parseJson(String json) { List<SubjectInfo> subjectInfos=new ArrayList<SubjectInfo>(); try { //[]需要JSONArray JSONArray jsonArray=new JSONArray(json); for(int i=0;i<jsonArray.length();i++){ //大括号需要getJSONObject，获取到大括号对象 JSONObject jsonObject = jsonArray.getJSONObject(i); String des=jsonObject.getString("des"); String url = jsonObject.getString("url"); SubjectInfo info=new SubjectInfo(des, url); subjectInfos.add(info); } return subjectInfos; } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; } } @Override public String getKey() { return "subject"; } } HomeProtocal.java

package com.ldw.market.protocol; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.StringWriter; import java.util.ArrayList; import java.util.List; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import com.ldw.market.domain.AppInfo; import com.ldw.market.http.HttpHelper; import com.ldw.market.http.HttpHelper.HttpResult; import com.ldw.market.utils.FileUtils; import com.lidroid.xutils.HttpUtils; import com.lidroid.xutils.exception.HttpException; import com.lidroid.xutils.http.ResponseStream; import com.lidroid.xutils.http.client.HttpRequest.HttpMethod; import com.lidroid.xutils.util.IOUtils; public class HomeProtocal extends BaseProtocol <List<AppInfo>>{ //解析json数据 public List<AppInfo> parseJson(String json) { List<AppInfo> appInfos = new ArrayList<AppInfo>(); try { JSONObject jsonObject = new JSONObject(json); //获取到中括号的内容 JSONArray jsonArray = jsonObject.getJSONArray("list"); //遍历list数组,list数组里面又是由大括号构成 for(int i = 0; i < jsonArray.length(); i++){ JSONObject jsonObj = jsonArray.getJSONObject(i); long id = jsonObj.getLong("id"); String name = jsonObj.getString("name"); String packageName = jsonObj.getString("packageName"); String iconUrl = jsonObj.getString("iconUrl"); float stars = Float.parseFloat(jsonObj.getString("stars")); long size = jsonObj.getLong("size"); String downloadUrl = jsonObj.getString("downloadUrl"); String des = jsonObj.getString("des"); //构造函数，创建一个appInfo AppInfo appInfo = new AppInfo(id, name, packageName, iconUrl, stars, size, downloadUrl, des); //往集合中添加对象 appInfos.add(appInfo); } return appInfos; } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); return null; } } @Override public String getKey() { // TODO Auto-generated method stub return "home"; } } SubjectFragment.java

package com.ldw.market.fragment; import java.util.List; import com.ldw.market.R; import com.ldw.market.domain.SubjectInfo; import com.ldw.market.fragment.BaseFragment.LoadResult; import com.ldw.market.http.HttpHelper; import com.ldw.market.protocol.SubjectProtocol; import com.ldw.market.utils.BitmapHelper; import com.ldw.market.utils.UiUtils; import com.lidroid.xutils.BitmapUtils; import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; public class SubjectFragment extends BaseFragment { private List<SubjectInfo> datas; @Override public View createSuccessView() { ListView listView=new ListView(UiUtils.getContext()); listView.setAdapter(new SubjectAdapter()); return listView; } private class SubjectAdapter extends BaseAdapter{ @Override public int getCount() { // TODO Auto-generated method stub return datas.size(); } @Override public Object getItem(int position) { // TODO Auto-generated method stub return datas.get(position); } @Override public long getItemId(int position) { // TODO Auto-generated method stub return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { View view; ViewHolder holder; if(convertView==null){ view=View.inflate(UiUtils.getContext(), R.layout.item_subject, null); holder=new ViewHolder(); holder.item_icon=(ImageView) view.findViewById(R.id.item_icon); holder.item_txt=(TextView) view.findViewById(R.id.item_txt); view.setTag(holder); }else{ view=convertView; holder=(ViewHolder) view.getTag(); } SubjectInfo info=datas.get(position); holder.item_txt.setText(info.getDes()); bitmapUtils.display(holder.item_icon, HttpHelper.URL+"image?name="+info.getUrl()); return view; } } class ViewHolder{ ImageView item_icon; TextView item_txt; } @Override protected LoadResult load() { SubjectProtocol protocol=new SubjectProtocol(); datas = protocol.load(0); return checkData(datas); } } subject页面的布局文件item_subject

<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" > <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginLeft="9dip" android:layout_marginRight="9dip" android:background="@drawable/list_item_bg" > <ImageView android:id="@+id/item_icon" android:layout_width="match_parent" android:layout_height="wrap_content" android:scaleType="fitCenter" android:src="@drawable/ic_default" android:padding="5dp"/> <TextView android:id="@+id/item_txt" style="@style/TitleStyle" android:layout_width="wrap_content" android:layout_height="match_parent" android:layout_below="@id/item_icon" android:gravity="center_vertical" android:paddingBottom="5dp" android:paddingLeft="5dp" android:paddingRight="5dp" android:singleLine="true" /> </RelativeLayout> </FrameLayout>在res/values/styles.xml中添加样式

<style name="TitleStyle"> <item name="android:textColor">@color/txt_title</item> <item name="android:textSize">@dimen/list_item_title_size</item> <item name="android:ellipsize">end</item> <item name="android:singleLine">true</item> </style>res/values/demons.xml中设置大小

<dimen name="list_item_title_size">16dp</dimen>res/values/colors.xml中设置颜色

<color name="txt_title">#333333</color>