Android SQLite公用结果处理 - 黑马程序员技术交流社区

package cn.com.choicesoft.weiqian.util;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import <a title="android" href="http://www.android-study.com/jichuzhishi/567.html">android</a>.content.Context;
import <a title="android" href="http://www.android-study.com/jichuzhishi/567.html">android</a>.database.Cursor;
import <a title="android" href="http://www.android-study.com/jichuzhishi/567.html">android</a>.database.<a title="sqlite" href="http://www.android-study.com/jichuzhishi/567.html">sqlite</a>.SQLiteDatabase;
/**
*@Author:M.c
*@Comments:数据库公用查询结果处理类
*@CreateDate:2014-1-20
*@Email:JNWSCZH@163.COM
*/
public class ListProcessor {
private DBManager db;
public DBManager getDb(Context context) {
if(db==null){
db = new DBManager(context);
}
return db;
}
/**
* 根据传入实体返回对应的实体数组
* @param sql SQL语句
* @param selectionArgs SQL条件
* @param context Activity
* @param cal 实体类【实体内属性只支持：String,Integer,Float,Double,Boolean,Short,Long,Character(char)】
* @return List<T>
*/
public <T> List<T> query(String sql,String[] selectionArgs,Context context,Class<T> cal){
SQLiteDatabase database = getDb(context).openDatabase();
Cursor c = database.rawQuery(sql, selectionArgs);
Method[] methods = cal.getMethods();
List<T> list=new ArrayList<T>();
while (c.moveToNext()) {
Object obj=null;
try {
obj=cal.newInstance();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
for (Method method : methods) {
String methodName=method.getName();
if(methodName.matches("^set[A-Z]\w+$")){
String name=methodName.substring(3, methodName.length()).toUpperCase();
for (int i=0;i<c.getColumnCount();i++) {
if(name.equalsIgnoreCase(c.getColumnName(i))){
try {
typeDivision(method,c.getString(i),cal,obj);
break;
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}
list.add((T)obj);
}
if(c!=null){
c.close();
}
if(database!=null){
database.close();
}
return list;
}
/**
* 不同类型转换
* @param method
* @param value
* @param cla
* @throws Exception
*/
public void typeDivision(Method method, Object value, Class<?> cls,Object obj) throws Exception {
Object typeName = method.getParameterTypes()[0];
Method setMethod = null;
if (typeName == String.class) {
setMethod = cls.getMethod(method.getName(), String.class);
setMethod.invoke(obj, value.toString());
}else if (typeName == Double.class||typeName.toString().equals("double")){
setMethod = cls.getMethod(method.getName(), typeName == Double.class?Double.class:double.class);
setMethod.invoke(obj, new Double(value.toString()));
}else if (typeName == Integer.class||typeName.toString().equals("int")) {
setMethod = cls.getMethod(method.getName(), typeName == Integer.class?Integer.class:int.class);
setMethod.invoke(obj, Integer.valueOf(value.toString()));
}else if (typeName == Long.class||typeName.toString().equals("long")) {
setMethod = cls.getMethod(method.getName(), typeName == Long.class?Long.class:long.class);
setMethod.invoke(obj, Long.valueOf(value.toString()));
} else if (typeName == Character.class||typeName.toString().equals("char")) {
setMethod = cls.getMethod(method.getName(),typeName == Character.class?Character.class:char.class);
setMethod.invoke(obj, value.toString().charAt(0));
} else if (typeName == Boolean.class||typeName.toString().equals("boolean")) {
setMethod = cls.getMethod(method.getName(), typeName == Boolean.class?Boolean.class:boolean.class);
setMethod.invoke(obj, new Boolean(value.toString()));
} else if (typeName == Float.class||typeName.toString().equals("float")) {
setMethod = cls.getMethod(method.getName(), typeName == Float.class?Float.class:float.class);
setMethod.invoke(obj, Float.valueOf(value.toString()));
} else if (typeName == Short.class||typeName.toString().equals("short")) {
setMethod = cls.getMethod(method.getName(), typeName == Short.class?Short.class:short.class);
setMethod.invoke(obj, Short.valueOf(value.toString()));
}
}
}

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