利用反射实现对sqlite3数据库的crud(增删改查)操作的一个baseAndroidDao封装,安卓开发中
1.说明
博主主要是做java web后台这一块,但是偶尔做点安卓,发现安卓上没有像Hibernate这种orm框架(....其实也没有去找),
又觉得每次增删改查都自己写代码的话肯定是非常麻烦的,所以就写了一个简单的baseAndroidDao来封装一些简单的增删改查操作;
需要注意的是,此框架并非一个健全的orm框架,功能简单,而且这些功能必须采用博主约定的方式才能正确运行;
2.具体实现
例举现在有一个javaBean如下,其如同Hibernate中的实体,但是却只是通过属性来存取值(博主嫌麻烦....没有用getter和setter那种标准方式,而且基本够用...)
public class User extends BaseEntity {
public Long Id;
public String Login_Name;
public String Password;
public String Real_Name;
public Long State;
public String Uid;
@Entity_FieldProperty(FieldType=FieldType.JsonObject,cls=Sys_User_Info.class)
public Sys_User_Info UserInfo;
@Override
public Long getId() {
return Id;
}
}
约定一:所有实体(用来存储和数据库表数据相对应的bean)必须继承BaseEntity类,
约定二:同时属性的名称必须和数据库中的字段相一致;不过,主键必须是Long Id(不区分大小写),数据库中将会以_id字段存储;
约定三:只支持Boolean,Date,Long,String,Integer,List,Objec,Float,Double这几个包装类的属性,不支持数组类型;
约定四.通过Entity_FieldProperty注解来实现对List,bean对象,静态对象的控制;
说明:这些约定都是很好改的.....如有需要可以下载之后自己该,最好是改成类似Hibernate那种注解识别id的方式,然后给博主发一份过来嘿嘿;
其中BaseEntity主要是封装一些对Entity的操作....具体代码如下(其实这些东东封装到Dao中,然后用Dao对Entity操作时最好的,这样Entity也不用继承BaseEntity)
以后有时间博主会重写结构然后更新(现在结构很垃圾..耦合重...),但是利用反射的核心代码不会这么变,所以大家可以看看:
/**
* Entity约定:
* 0.主键的名称必须是id,不分大小写,数据库中以_id存储
* 1.只支持Boolean,Date,Long,String,Integer,List,Objec,Float,Double这几个包装类的属性,不支持数组类型
* 2.其它属性的值,不支持自动赋值与使用
* 3.通过Entity_FieldProperty注解来实现对List,bean对象,静态对象的控制;
* @author dview
*
*/
public abstract class BaseEntity {
/**
* 下面规定允许的数据类型
*/
@JSONField(serialize=false)
private final String type_boolean="class java.lang.Boolean",
type_date="class java.util.Date",
type_float="class java.lang.Float",
type_double="class java.lang.Double",
type_long="class java.lang.Long",
type_integer="class java.lang.Integer",
type_string="class java.lang.String";
@JSONField(serialize=false)
public final static String primaryKeyName="_id";
/**
* 判断一个属性是否是静态变量,此类暂时不用
* @param field
*/
@JSONField(serialize=false)
public boolean isStaticField(Field field){
boolean isStatic = Modifier.isStatic(field.getModifiers());
return isStatic;
}
/**
* 为本实体类赋值
* @throws IllegalArgumentException
* @throws IllegalAccessException
*/
@JSONField(serialize=false)
private void setFieldValue(Cursor c) throws IllegalAccessException, IllegalArgumentException{
if(c==null) return;
Class<?> clazz=this.getClass();
Field[] fs=clazz.getDeclaredFields();
for(Field f:fs){
int index=0;//cursor游标中的索引,某个字段
try{
f.setAccessible(true);//强制获取,设置值
Annotation[] as=f.getAnnotations();
Class<?> fclass=null;
FieldType fType=null;
for(int i=0;i<as.length;i++){
Annotation a=as[i];
if(a instanceof Entity_FieldProperty){
Entity_FieldProperty ef=(Entity_FieldProperty)a;
if(ef!=null){
fclass=ef.cls();
fType=ef.FieldType();
}
break;
}
}
String typeString=f.getGenericType().toString();
String name=f.getName();
if(name.toLowerCase(Locale.ENGLISH).equals("id"))
{
name=primaryKeyName;
}
index=c.getColumnIndex(name);
if(index==-1)
continue;
//按照基础六类属性来处理
if(fType==null||fType==FieldType.Base){
if(typeString.equals(type_boolean)){
int result=c.getInt(index);
f.set(this, (Boolean)(result==1));
}else if(typeString.equals(type_date)){
Long m=c.getLong(index);
if(m!=null)
{
f.set(this, new Date(m));
}else{
f.set(this,null);
}
}else if(typeString.equals(type_integer)){
f.set(this,c.getInt(index));
}else if(type_long.equals(typeString)){
f.set(this,c.getLong(index));
}else if(typeString.equals(type_float)){
f.set(this,c.getFloat(index));
}else if(typeString.equals(type_double)){
f.set(this,c.getDouble(index));
}else{
f.set(this,c.getString(index));
}
}else if(fType==FieldType.Transient){
continue;
}else if(fType==FieldType.JsonObject){
Object jobj=null;
if(c.getString(index)!=null)
JsonUtils_wg.parseToObject(c.getString(index), fclass);
f.set(this,jobj);
}else if(fType==FieldType.JsonList){
List<?> objs = null;
if(c.getString(index)!=null)
objs=JsonUtils_wg.parseToArray(c.getString(index), fclass);
f.set(this,objs);
}
} catch (Exception e) {
Log.e(this.getClass().getName(), e.toString());
e.printStackTrace();
continue;
}//end try
}//end for
}
/**
* 以键值对的方式,返回单签类的,属性的名称和之所对应的值
* @return
* @param isChangeIdString 是否改变属性名称为id的键为BaseEntity.primaryKeyName所代表的属性值
* @throws IllegalArgumentException
* @throws IllegalAccessException
*/
@JSONField(serialize=false)
private Map<String,Object> getFieldValue(boolean isChangeIdString) throws IllegalAccessException, IllegalArgumentException{
Map<String,Object> maps=new HashMap<String,Object>();
Class<?> clazz=this.getClass();
Field[] fs=clazz.getDeclaredFields();
for(Field field:fs){
field.setAccessible(true);
Annotation[] as=field.getAnnotations();
Class<?> fclass=null;
FieldType fType=null;
for(int i=0;i<as.length;i++){
Annotation a=as[i];
if(a instanceof Entity_FieldProperty){
Entity_FieldProperty ef=(Entity_FieldProperty)a;
if(ef!=null){
fclass=ef.cls();
fType=ef.FieldType();
}
break;
}
}
String typeString=field.getGenericType().toString();
String name=field.getName();
if(name.toLowerCase(Locale.ENGLISH).equals("id")&&isChangeIdString)
{
name=primaryKeyName;
}
//按照基础六类属性来处理
if(fType==null||fType==FieldType.Base){
if(field.get(this)==null){
maps.put(name, null);
}else if(typeString.equals(type_boolean)){
if((Boolean)field.get(this))
{
maps.put(name,1);
}
else{
maps.put(name,0);
}
}else if(typeString.equals(type_date)){
Date d=(Date) field.get(this);
maps.put(name, d.getTime());
}else {
maps.put(name,field.get(this));
}
}else if(fType==FieldType.Transient){
continue;
}else if(fType==FieldType.JsonObject){
if(field.get(this)==null)
{
maps.put(name,"{}");
}else{
String jsonString=JSON.toJSONString(field.get(this));
maps.put(name,jsonString);
}
}else if(fType==FieldType.JsonList){
if(field.get(this)==null)
{
maps.put(name,"[]");
}else{
String jsonString=JSON.toJSONString(field.get(this));
maps.put(name,jsonString);
}
}
}
return maps;
}
//通过Cursor自动将值赋值到实体
@JSONField(serialize=false)
public void initFromCursor(Cursor c) throws IllegalAccessException, IllegalArgumentException{
setFieldValue(c);
}
@JSONField(serialize=false)
public ContentValues getContentValues() throws IllegalAccessException, IllegalArgumentException
{
ContentValues cv;
cv=new ContentValues();
Map<String,Object> maps=getFieldValue(true);
Set<String> keys=maps.keySet();
for(String s:keys){
try{ Object obj=maps.get(s);
String typeString=obj.getClass().getName();
if(obj==null){
cv.put(s,"");
}else if(typeString.equals(type_boolean)){
cv.put(s,(Boolean)(obj));
}else if(typeString.equals(type_date)){
cv.put(s,((Date)(obj)).getTime());
}else if(typeString.equals(type_integer)){
cv.put(s,(Integer)(obj));
}else if(type_long.equals(typeString)){
cv.put(s,((Long)(obj)));
}else if(typeString.equals(type_float)){
cv.put(s,(Float)(obj));
}else if(typeString.equals(type_double)){
cv.put(s,(Double)(obj));
}else if(typeString.equals(type_string)){
cv.put(s,(String)(obj));
}else{
cv.put(s,JSON.toJSONString(obj));
}
} catch (Exception e) {
Log.e(this.getClass().getName(), e.toString());
e.printStackTrace();
continue;
}
}//end for
return cv;
}
/**
* 返回该类属性的键值对,键和值均为String类型
* @return
* @throws IllegalAccessException
* @throws IllegalArgumentException
*/
@JSONField(serialize=false)
public Map<String,Object> getMapValues() throws IllegalAccessException, IllegalArgumentException
{
return getFieldValue(false);
}
@JSONField(serialize=false)
public void saveToDataBase(String tableName,SQLiteDatabase db) throws Exception{
if(getId()==0)
throw new Exception("存储的_id号码不能够是0,请稍后再试!");
Map<String,Object> maps=getFieldValue(true);
Set<String> keys=maps.keySet();
Object[] objs=new Object[keys.size()];
String q="";
String sql="insert into "+tableName.trim()+"(";
int i=0;
for(String s:keys){
Object obj=maps.get(s);
if(i!=0)
{
sql+=",";
q+=",";
}
sql+=s;
q+="?";
objs[i]=obj;
i++;
}
sql+=") values ("+q+")";
db.execSQL(sql, objs);
}
@JSONField(serialize=false)
public void updateToDataBase(String tableName,SQLiteDatabase db) throws Exception{
if(getId()==0)
throw new Exception("更新的_id号码不能够是0,请稍后再试!");
this.updateToDataBaseByColumn(tableName, db, primaryKeyName);
}
/**
*
* @param tableName
* @param db
* @param columnName 指定此此表的一个列名称,更新所有相同的记录
* @throws Exception
*/
@JSONField(serialize=false)
public void updateToDataBaseByColumn(String tableName,SQLiteDatabase db,String columnName) throws Exception{
if(columnName==null)
throw new Exception("更新的columnName不能够是null,请稍后再试!");
Map<String,Object> maps=getFieldValue(true);
Set<String> keys=maps.keySet();
Object[] objs=new Object[keys.size()+1];
String sql="update "+tableName.trim()+" set ";
int i=0;
for(String s:keys){
Object obj=maps.get(s);
if(i!=0)
{
sql+=",";
}
sql+=s+"=?";
objs[i]=obj;
if(s.equals(columnName)){
objs[keys.size()]=obj;
}
i++;
}
sql=sql+" where "+columnName+"=?";
db.execSQL(sql, objs);
//data.close();
}
/**
*
* @param tableName
* @param data
* @param notUpdateColumns 不需要跟新的字段,区分大小写
* @throws Exception
*/
@JSONField(serialize=false)
public void updateToDataBase(String tableName,SQLiteDatabase db,String[] notUpdateColumns) throws Exception{
if(getId()==0)
throw new Exception("更新的_id号码不能够是0,请稍后再试!");
Map<String,Object> maps=getFieldValue(true);
Set<String> keys=maps.keySet();
Object[] objs;
Map<String,Object> updateMap=new HashMap<String,Object>();
String sql="update "+tableName.trim()+" set ";
int i=0;
for(String s:keys){//筛选出来需要更新的数据
boolean need=true;
if(notUpdateColumns!=null)
for(String c:notUpdateColumns){
if(c.equals(s))
{
need=false;
break;
}
}
if(need){
updateMap.put(s,maps.get(s));
}
}
Set<String> key=updateMap.keySet();
objs=new Object[key.size()+1];
i=0;
for(String s:key){
Object value=updateMap.get(s);
if(i!=0)
{
sql+=",";
}
sql+=s+"=?";
objs[i]=value;
if(s.equals(primaryKeyName))
{ objs[key.size()]=value; }
i++;
}
sql=sql+" where "+primaryKeyName+"=?";
db.execSQL(sql, objs);
}
@Override
public boolean equals(Object o) {
if(this.getClass().getName().equals(o.getClass().getName())&&this.getId()-((BaseEntity)o).getId()==0)
return true;
return super.equals(o);
}
@Override
public int hashCode() {
return getId().intValue();
}
public abstract Long getId();
}
其中Entity_FieldProperty这个注解主要是帮助我们对对象和List进行存储以及读取,说白了就是简单的将之转化为json字符串,然后进行相关的序列号与反序列化;
至于List嵌套和对象嵌套的反序列化,可以查看博文http://blog.csdn.net/huitoukest/article/details/50071867
/**
* 指定当前Entity中的属性的属性,即自生的类别和转换的方式
* @author dview76
* 当FieldType.Base的时候,将会按照默认识别的类型使用,即此时的cls属性不会生效
* JsonList,JsonObject,Base,Transient
* JsonList,JsonObject表示此对象需要转换为一个json对象或者字符串;
* Transient表示此对象,不进行数据库的存和取操作,选择Transient的时候,cls属性不会生效
*/
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Entity_FieldProperty {
/**
* 指定一个类型是FieldType的,表现为FieldType=默认为FieldType.Base的Annotation
* @return
*/
FieldType FieldType() default FieldType.Base;
/**
* 指定一个类型是Class的,表现为cls=默认为String.class的Annotation
* @return
*/
Class cls() default String.class;
/**
* 指定当前属性的类型
*
*/
public enum FieldType{
JsonList,JsonObject,Base,Transient;
};
}
之后是主角BaseAndroidDao,其实就是增删改查方法的封装:
约定如下:此dao中不会管理事务;
/**
* Dao中不会管理事务,事务在Service层中进行管理
* @author dview
*
*/
public class BaseAndroidDao<T extends BaseEntity> {
private String tableName;
private DataBaseManager dbManager;
public BaseAndroidDao(String tableName) {
super();
this.dbManager=DataBaseManager.getInstance();
this.tableName = tableName;
}
public SQLiteDatabase openDataBase(){
return dbManager.openDatabase();
}
public void closeDataBase(){
dbManager.closeDatabase();
}
/**
* 得到当前的最大的id号码的值
* @param db
* @return
*/
public Long getMaxId(SQLiteDatabase db){
Cursor c=null;
c=this.getCursor(db,tableName,null,"select max("+T.primaryKeyName+") ", null,null,null,null,null);
if(c.moveToNext()){
return c.getLong(c.getColumnIndex(T.primaryKeyName));
}else return null;
}
/**
* 得到当前的最小的id号码的值
* @param db
* @return
*/
public Long getMinId(SQLiteDatabase db){
Cursor c=null;
c=this.getCursor(db,tableName,null,"select min("+T.primaryKeyName+") ", null,null,null,null,null);
if(c.moveToNext()){
return c.getLong(0);
}else return null;
}
/**
* 得到当前的的记录总数
* @param db
* @return
*/
public Long getCount(SQLiteDatabase db){
Cursor c=null;
c=this.getCursor(db,tableName,null,"select count(*) ", null,null,null,null,null);
if(c.moveToNext()){
return c.getLong(0);
}else return null;
}
/**
* 返回所保存到数据库中的列表
* @param entity
* @return
*/
protected List<String> getEntityColumnNameList(Class<?> cls){
List<String> list=new ArrayList<String>();
Class<?> clazz=cls;
Field[] fs=clazz.getDeclaredFields();
String filedName=null;
for(Field field:fs){
field.setAccessible(true);
filedName=field.getName();
Annotation[] as=field.getAnnotations();
Class fclass=null;
FieldType fType=null;
for(int i=0;i<as.length;i++){
Annotation a=as[i];
if(a instanceof Entity_FieldProperty){
Entity_FieldProperty ef=(Entity_FieldProperty)a;
if(ef!=null){
fclass=ef.cls();
fType=ef.FieldType();
}
break;
}
}
if(fType==null||fType!=FieldType.Transient)
list.add(filedName);
}
return list;
}
/*
*得到除开指定名称的属性列
*/
public String[] getEntityColumnNames(Class<?> cls,Boolean isRepacePrimaryKeyName,String... exceptCoulums){
List<String> nameList=getEntityColumnNameList(cls);
if(isRepacePrimaryKeyName==null){
isRepacePrimaryKeyName=true;
}
if(exceptCoulums!=null){
for(String s:exceptCoulums){
nameList.remove(s);
}
}
String[] names=new String[nameList.size()];
for(int i=0;i<nameList.size();i++){
names[i]=nameList.get(i);
if(names[i].toLowerCase(Locale.ENGLISH).equals("id")){
names[i]=BaseEntity.primaryKeyName;
}
}
return names;
}
/**失败返回null
* 传入代Id值的Entity的值实例
* @param t 返回t
* @return
* @throws Exception
*/
public T get(SQLiteDatabase db,T t) throws Exception{
if(t==null) return null;
Cursor c=null;
try {
c=this.getCursor(db,tableName, null, T.primaryKeyName+"=?", new String[]{t.getId()+""}, null, null, null,null);
if(c.moveToNext())
{ t.initFromCursor(c);
return t;
}else{
return null;
}
} catch (Exception e) {
Log.e(this.getClass().getName()+"T get:",e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**手动的条件搜索
* @return
* @throws Exception
*/
public T get(SQLiteDatabase db,Class<T> cls,String[] columns,String selection, String[] selectionArgs, String orderBy) throws Exception{
Cursor c=null;
try {
c=this.getCursor(db,tableName,columns, selection, selectionArgs, null, null, orderBy,"0,1");
if(c.moveToNext())
{ T t=cls.newInstance();
t.initFromCursor(c);
return t;
}else{
return null;
}
} catch (Exception e) {
Log.e(this.getClass().getName()+"T get:",e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**失败返回null
* 传入代Id值的Entity的值实例
* @param t 返回t
* @param exceptCoulums 不需要取出的数据列的名称
* @return
* @throws Exception
*/
public T get(SQLiteDatabase db,T t,String... exceptCoulums) throws Exception{
if(t==null) return null;
Cursor c=null;
try {
String[] names=getEntityColumnNames(t.getClass(), true,exceptCoulums);
c=this.getCursor(db,tableName,names, T.primaryKeyName+"=?", new String[]{t.getId()+""}, null, null, null,null);
if(c.moveToNext())
{ t.initFromCursor(c);
return t;
}else{
return null;
}
} catch (Exception e) {
Log.e(this.getClass().getName()+"T get:",e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**
*
* 失败返回空数组
* @param db
* @param cls
* @param selection
* @param selectionArgs
* @param orderBy
* @param limit select * from table_name limit N,M //N序号从0开始
* @param exceptCoulums 指定不从数据库取出的列
* @return
* @throws Exception
*/
public List<T> getList(SQLiteDatabase db,Class<T> cls,String selection, String[] selectionArgs, String orderBy,String limit,String... exceptCoulums) throws Exception{
List<T> ts=new ArrayList<T>();
Cursor c = null;
try {
String[] names=getEntityColumnNames(cls, true, exceptCoulums);
c=this.getCursor(db,tableName,names, selection, selectionArgs, null, null, orderBy,limit);
while(c.moveToNext()){
T t=cls.newInstance();
t.initFromCursor(c);
if(!ts.contains(t))
ts.add(t);
}
} catch (Exception e) {
Log.e("getList:"+cls.getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
return ts;
}
/**
* 失败返回空数组
* @param db
* @param cls
*@param selection
* @param selectionArgs
* @param orderBy
* @param limit select * from table_name limit N,M //N序号从0开始
* @return
* @throws Exception
*/
public List<T> getList(SQLiteDatabase db,Class<T> cls,String selection, String[] selectionArgs, String orderBy,String limit) throws Exception{
List<T> ts=new ArrayList<T>();
Cursor c = null;
try {
c=this.getCursor(db,tableName, null, selection, selectionArgs, null, null, orderBy,limit);
while(c.moveToNext()){
T t=cls.newInstance();
t.initFromCursor(c);
if(!ts.contains(t))
ts.add(t);
}
} catch (Exception e) {
Log.e("getList:"+cls.getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
return ts;
}
/**
* 获取数据库中的所有的记录
* @param db
* @param cls
* @return
* @throws Exception
*/
public List<T> getList(SQLiteDatabase db,Class<T> cls) throws Exception{
List<T> ts=new ArrayList<T>();
Cursor c = null;
try {
c=this.getCursor(db,tableName, null,null,null, null, null,null,null);
while(c.moveToNext()){
T t=cls.newInstance();
t.initFromCursor(c);
if(!ts.contains(t))
ts.add(t);
}
} catch (Exception e) {
Log.e("getList:"+cls.getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
return ts;
}
/**
*
* @param t
* @return 插入返回1
* @throws Exception
*/
public void saveOrUpdate(SQLiteDatabase db,T t) throws Exception{
Cursor c = null;
try {
c=this.getCursor(db,tableName, null, T.primaryKeyName+"=?", new String[]{t.getId()+""}, null, null, null,null);
if(c.moveToNext())
{//如果已经存在,则更新,否则insert
t.updateToDataBase(tableName,db);
return;
}
t.saveToDataBase(tableName,db);
return;
} catch (Exception e) {
Log.e("saveOrUpdate:"+t.getClass().getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**
*
* @param t
* @return 插入返回1
* @param columnName 如果指定的字段,有相同的值存在于数据库,那么就更新数据库,否则保存
* @throws Exception
*/
public void saveOrUpdate(SQLiteDatabase db,T t,String columnName) throws Exception{
Cursor c = null;
try {
c=this.getCursor(db,tableName, null, columnName+"=?", new String[]{t.getClass().getField(columnName).get(t)+""}, null, null, null,null);
if(c.moveToNext())
{//如果已经存在,则更新,否则insert
t.updateToDataBaseByColumn(tableName, db, columnName);
return;
}
t.saveToDataBase(tableName,db);
return;
} catch (Exception e) {
Log.e("saveOrUpdate:"+t.getClass().getName(),e.toString());
throw e;
}finally{
if(c!=null) c.close();
}
}
/**
* 先删除,后保存,没有则不删除
* @param db
* @param t
* @throws Exception
*/
public void deleteAndSave(SQLiteDatabase db,T t) throws Exception{
try {
this.delete(db, t.getId()+"");
this.save(db, t);
} catch (Exception e) {
Log.e("saveOrUpdate:"+t.getClass().getName(),e.toString());
throw e;
}
}
/**
*
* @param db
* @param list
* @return
* @throws Exception
*/
public void saveOrUpdateList(SQLiteDatabase db,List<T> list) throws Exception{
try{
for(T t:list){
saveOrUpdate(db, t);
}
}catch(Exception e){
throw new Exception("saveOrUpdateList: "+" Fail");
}
}
/**
*
* @param db
* @param list
* @param column 指定列的值相同就更新,否则就保存
* @throws Exception
*/
public void saveOrUpdateList(SQLiteDatabase db,List<T> list,String column) throws Exception{
try{
for(T t:list){
saveOrUpdate(db, t,column);
}
}catch(Exception e){
throw new Exception("saveOrUpdateList: "+" Fail");
}
}
/**
*删除后保存所有
* @param db
* @param list
* @return
* @throws Exception
*/
public void deleteAndSaveList(SQLiteDatabase db,List<T> list) throws Exception{
try{
for(T t:list){
deleteAndSave(db, t);
}
}catch(Exception e){
throw new Exception("saveOrUpdateList: "+" Fail");
}
}
public int update(SQLiteDatabase db,T t) throws Exception{
try {
t.updateToDataBase(tableName,db);
return 2;
} catch (Exception e) {
Log.e("update:"+t.getClass().getName(),e.toString());
throw e;
}
}
/**
*
* @param t
* @param notUpdateColumns 不需要更新的字段名称的数组
* @return
* @throws Exception
*/
public int update(SQLiteDatabase db,T t,String[] notUpdateColumns) throws Exception{
try {
t.updateToDataBase(tableName,db,notUpdateColumns);
return 2;
} catch (Exception e) {
Log.e("update:"+t.getClass().getName(),e.toString());
throw e;
}
}
public int save(SQLiteDatabase db,T t) throws Exception{
try {
t.saveToDataBase(tableName, db);
return 1;
} catch (Exception e) {
Log.e("save:"+t.getClass().getName(),e.toString());
throw e;
}
}
public int delete(SQLiteDatabase db,String id) throws Exception{
if(id.equals("0"))
throw new Exception("删除的_id号码不能够是0,请稍后再试!");
try {
this.delete(db,tableName, id);
return 1;
} catch (Exception e) {
Log.e("delete:"+this.getClass().getName(),e.toString());
throw e;
}
}
public int deleteList(SQLiteDatabase db,String ids) throws Exception{
try {
String whereClause=" "+T.primaryKeyName+" in (?)";
String[] whereArgs=new String[]{ids};
this.delete(db,tableName, whereClause, whereArgs);
return 1;
} catch (Exception e) {
Log.e("deleteList:"+this.getClass().getName(),e.toString());
throw e;
}
}
public int deleteAll(SQLiteDatabase db) throws Exception{
try {
this.delete(db,tableName, null,null);
return 1;
} catch (Exception e) {
Log.e("deleteAll:"+this.getClass().getName(),e.toString());
throw e;
}
}
/**
* 返回搜索的cursor;
* @param db
* @param sqlString
* @param selectionArgs sql中?占位符的参数
* @return
*/
public Cursor getCursor(SQLiteDatabase db,String sqlString,String[] selectionArgs){
return db.rawQuery(sqlString,selectionArgs);
}
/**
*
* @param db
* @param sqlString
* @param selectionArgs sql中?占位符的参数
* @param columns 需要出去的列的名称,没有会赋值null;取出的列只支持float/string/blob/string/null这几种类型;
* *其中二进制会转换成为byte[]类型;除开这些类型外,系统会默认用string来取出数据
* @return List<Object[]>
*/
public List<Object[]> getColumns(SQLiteDatabase db,String sqlString,String[] selectionArgs,String...columns){
List<Object[]> list=new ArrayList<Object[]>();
Object[] objs=null;
Cursor cursor=getCursor(db, sqlString, selectionArgs);
while(cursor.moveToNext()){
objs=new Object[columns.length];
try{
for(int i=0;i<columns.length;i++){
String ss=columns[i];
int index=cursor.getColumnIndex(ss);
if(index==-1)
continue;
int columnType =cursor.getType(index);
switch (columnType) {
case Cursor.FIELD_TYPE_NULL:
objs[i]=null;
break;
case Cursor.FIELD_TYPE_INTEGER:
objs[i]=cursor.getInt(index);
break;
case Cursor.FIELD_TYPE_BLOB:
objs[i]=cursor.getBlob(index);
break;
case Cursor.FIELD_TYPE_FLOAT:
objs[i]=cursor.getFloat(index);
break;
case Cursor.FIELD_TYPE_STRING:
objs[i]=cursor.getString(index);
break;
default:
objs[i]=cursor.getString(index);
break;
}
}
list.add(objs);
}catch(ClassCastException e){
e.printStackTrace();
Log.e("BaseAndroidDao:getColumns:",e.toString());
}
}
return list;
}
public Cursor getCursor(SQLiteDatabase db,String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy,String limit) {
Cursor cursor = db.query(table, columns, selection, selectionArgs, groupBy, having, orderBy,limit);
return cursor;
}
public void execSQL(SQLiteDatabase db,String sql){
db.execSQL(sql);
}
public void execSQL(SQLiteDatabase db,String sql,Object[] objs){
db.execSQL(sql,objs);
}
/**
* 调用原生的insert方法,不推荐
* @param tableName
* @param cv
* @return
*/
public long insert(SQLiteDatabase db,String tableName,ContentValues cv)
{
long row = db.insert(tableName, null, cv);
return row;
}
/**
* 调用自己写的方法,insert into person(name,phone) values (?,?)
* @param p
*/
public void save(SQLiteDatabase db,String sql,Object[] objs)
{
db.execSQL(sql, objs);
}
public void update(SQLiteDatabase db,String sql,Object[] objs){
db.execSQL(sql, objs);
}
//删除操作
public void delete(SQLiteDatabase db,String tableName,String id)
{
String where =BaseEntity.primaryKeyName + "=?";
String[] whereValue ={id};
db.delete(tableName, where, whereValue);
}
//删除操作
public void delete(SQLiteDatabase db,String table, String whereClause, String[] whereArgs)
{
db.delete(table, whereClause, whereArgs);
}
//修改操作
public void update(SQLiteDatabase db,String tableName,int id, ContentValues cv)
{
String where = BaseEntity.primaryKeyName+ "=?";
String[] whereValue = { Integer.toString(id) };
db.update(tableName, cv, where, whereValue);
}
//修改操作
public void update(SQLiteDatabase db,String tableName,ContentValues cv, String where,String[] whereValue)
{
db.update(tableName, cv, where, whereValue);
}
public String getTableName() {
return tableName;
}
public void setTableName(String tableName) {
this.tableName = tableName;
}
}
3:使用示例:
public class LoginTypeService {
private String tableName="loginType";
private BaseAndroidDao<LoginType> baseDao;
public LoginTypeService(){
baseDao=new BaseAndroidDao<LoginType>(tableName);
}
public LoginType getLoginType(){
LoginType lt=new LoginType();
lt.setId(1L);
SQLiteDatabase db = null;
try {
db=baseDao.openDataBase();
lt=baseDao.get(db, lt);
return lt;
} catch (Exception e) {
return null;
}finally{
baseDao.closeDataBase();
}
}
public boolean saveOrUpdate(LoginType loginType){
if(loginType==null||loginType.getId()==null)
return false;
SQLiteDatabase db = null;
try {
db=baseDao.openDataBase();
db.beginTransaction();
baseDao.saveOrUpdate(db, loginType);
db.setTransactionSuccessful();
return true;
} catch (Exception e) {
return false;
}finally{
if(db!=null)
db.endTransaction();
baseDao.closeDataBase();
}
}
}
注意:Service层,就是是控制层来负责事务的管理;