批量获取服务器的信息，显示在本地 不向服务器发信息直接获取
定义一个类，访问服务器并显示在这个页面显示在一个简单的ListView里面
访问服务器的类
定义初始化
//显示信息的ListView private ListView lv_leave; //填充访问服务器类的Adapter LeaveInfoAdapter lva; ArrayList<LeaveInfo> list = new ArrayList<LeaveInfo>();
在onCreate方法里面开始访问
setContentView(R.layout.leave_show);
lv_leave = (ListView) findViewById(R.id.leave_show_list);
try {
//将访问服务器获取到的值都保存在list里面
list = JSONUtil.postRequest("http://172.16.10.131:8080/workflow/workapprove!phoneFindStatus02.action");
//然后将这个list传给填充访问服务器类的Adapter
lva = new LeaveInfoAdapter(list, this);
//将Adapter赋值给ListView
lv_leave.setAdapter(lva);
} catch (Exception e) {
System.out.println("网络异常");
e.printStackTrace();
}
JsonUtil解析将获取到的值保存在一个list里面并传到访问服务器类里面定义的list里面
public class JSONUtil {
private static final String TAG = "JSONUtil";
/**
* 获取json内容
*
* @param url
* @return JSONArray
* @throws JSONException
* @throws ConnectionException
*/
public static JSONObject getJSON(String url) throws JSONException,
Exception {
return new JSONObject(getRequest(url));
}
/**
* 向api发送get请求，返回从后台取得的信息。
*
* @param url
* @return String
*/
protected static String getRequest(String url) throws Exception {
return getRequest(url, new DefaultHttpClient(new BasicHttpParams()));
}
protected static ArrayList<LeaveInfo> postRequest(String url)
throws Exception {
return postRequest(url, new DefaultHttpClient());
}
/**
* 向api发送get请求，返回从后台取得的信息。
*
* @param url
* @param client
* @return String
*/
protected static String getRequest(String url, DefaultHttpClient client)
throws Exception {
String result = null;
int statusCode = 0;
HttpGet getMethod = new HttpGet(url);
Log.d(TAG, "do the getRequest,url=" + url + "");
try {
// getMethod.setHeader("User-Agent", USER_AGENT);
HttpResponse httpResponse = client.execute(getMethod);
statusCode = httpResponse.getStatusLine().getStatusCode();
Log.d(TAG, "statuscode = " + statusCode);
result = retrieveInputStream(httpResponse.getEntity());
} catch (Exception e) {
Log.e(TAG, e.getMessage());
throw new Exception(e);
} finally {
getMethod.abort();
}
return result;
}
protected static ArrayList<LeaveInfo> postRequest(String url,
DefaultHttpClient client) throws Exception {
String result = null;
int statusCode = 0;
ArrayList<LeaveInfo> list = new ArrayList<LeaveInfo>();
HttpPost getMethod = new HttpPost(url);
Log.d(TAG, "do the postRequest,url=" + url + "");
try {
// getMethod.setHeader("User-Agent", USER_AGENT);
HttpResponse httpResponse = client.execute(getMethod);
// statusCode == 200 正常
statusCode = httpResponse.getStatusLine().getStatusCode();
Log.d(TAG, "statuscode = " + statusCode);
// 处理返回的httpResponse信息
if (statusCode == 200) {
HttpEntity entity = httpResponse.getEntity();
result = retrieveInputStream(entity);
JSONArray jsonArray = new JSONArray(result );
System.out.println(jsonArray);
for (int i = 0, size = jsonArray.length(); i < size; i++) {
LeaveInfo bean = new LeaveInfo();
JSONObject jsonObject = jsonArray.getJSONObject(i);
bean.setId(jsonObject.getInt("id"));
bean.setApplyname(jsonObject.getString("applyname"));
bean.setApplytime(jsonObject.getString("applytime"));
bean.setReason(jsonObject.getString("reason"));
bean.setStatus(jsonObject.getString("status"));
list.add(bean);
}
}
} catch (Exception e) {
// Log.e(TAG, e.getMessage());
throw new Exception(e);
} finally {
// getMethod.abort();
}
return list;
}
/**
* 处理httpResponse信息,返回String
*
* @param httpEntity
* @return String
*/
protected static String retrieveInputStream(HttpEntity httpEntity) {
int length = (int) httpEntity.getContentLength();
// the number of bytes of the content, or a negative number if unknown.
// If the content length is known but exceeds Long.MAX_VALUE, a negative
// number is returned.
// length==-1，下面这句报错，println needs a message
if (length < 0)
length = 10000;
StringBuffer stringBuffer = new StringBuffer(length);
try {
InputStreamReader inputStreamReader = new InputStreamReader(
httpEntity.getContent(), "UTF-8");
char buffer[] = new char[length];
int count;
while ((count = inputStreamReader.read(buffer, 0, length - 1)) > 0) {
stringBuffer.append(buffer, 0, count);
}
} catch (UnsupportedEncodingException e) {
Log.e(TAG, e.getMessage());
} catch (IllegalStateException e) {
Log.e(TAG, e.getMessage());
} catch (IOException e) {
Log.e(TAG, e.getMessage());
}
System.out.println("resulte:" + stringBuffer.toString());
return stringBuffer.toString();
}
}
填充访问服务器类的Adapter
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public class LeaveInfoAdapter extends BaseAdapter {
List<LeaveInfo> list;
Context mcontext;
public LeaveInfoAdapter(List<LeaveInfo> list, Context context) {
this. list = list;
this.mcontext = context;
}
public void setResult(List<LeaveInfo> list, Context context) {
this. list = list;
this.mcontext = context;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return list.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) {
if (convertView == null) {
LayoutInflater inflater = LayoutInflater.from(mcontext);
convertView = inflater.inflate(R.layout.leave, null);
}
TextView tv_name = (TextView) convertView.findViewById(R.id.leave_name);
tv_name.setText( "姓名:"+list.get(position).getApplyname());
TextView tv_time = (TextView) convertView.findViewById(R.id.leave_time);
tv_time.setText("请假时间"+ list.get(position).getApplytime());
TextView tv_reason = (TextView) convertView
.findViewById(R.id.leave_reason);
tv_reason.setText( "请假原因"+list.get(position).getReason());
TextView tv_status = (TextView) convertView
.findViewById(R.id.leave_status);
tv_status.setText( "状态:"+list.get(position).getStatus());
return convertView;
}
}
LeaveInfo 实体对象
public class LeaveInfo {
private int id ;
private String applyname ;
private String applytime ;
private String reason ;
private String status ;
然后是Getters跟Setters方法
有参构造方法跟无参构造方法
}
然后就是定义一个leave_show.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<ListView
android:id="@+id/leave_show_list"
android:layout_width="wrap_content"
android:layout_height="wrap_content"></ListView>
</LinearLayout>
定义一个填充Adapter的XMl leave.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/leave_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/leave_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/leave_reason"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
/>
<TextView
android:id="@+id/leave_status"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
以上代码就是android客户端直接访问服务器获取数据并显示在本地的ListView的实例