1、将sqlite的最轻量orm框架优化
private Lock writeLock = new ReentrantLock();
private volatile boolean writeLocked = false;
private void lock() {
writeLock.lock();
writeLocked = true;
}
private void unlock() {
if (writeLocked) {
writeLock.unlock();
writeLocked = false;
}
}
/**
* 保存
* @param obj
*/
public void save(Object obj) {
if (obj == null)
return;
try{
lock();
checkOrCreateTable(obj.getClass());
sqlProxy proxy = sqlProxy.save(obj);
db.execsql(proxy.getsql(),proxy.paramsArgs());
}finally{
unlock();
}
}
3、添加数据库表字段动态增删改
/**
* 检查表
* @param clazz
*/
private void checkOrCreateTable(Class<?> clazz) {
EntityInfo entity = EntityInfo.build(clazz);
if (entity.isChecked())
return;
Cursor cursor = db.rawQuery("SELECT name FROM sqlite_master WHERE type='table' and name='"+entity.getTable()+"' order by name",null);
Integer count = cursor != null ? cursor.getCount() : null;
if(cursor != null)
cursor.close();
if(count != null && count > 0){
String [] columnNames = getColumnNames(db,entity.getTable());
if(columnNames != null && columnNames.length > 0){
if(changeTable(clazz,columnNames)){
String columns = "";
boolean first = true;
List<ColumnInfo> list = entity.getColumnList();
for(int i=0,length=columnNames.length;i<length;i++){
for(ColumnInfo mColumnInfo : list){
if(mColumnInfo.getColumName().equals(columnNames)){
columns += (first ? "" : ",")+columnNames;
first = false;
}
}
}
if(TextUtils.isEmpty(columns)){
//删除
db.execsql("DROP TABLE " + entity.getTable());
//创建表
String sql = getCreatTablesql(clazz);
db.execsql(sql);
}else{
String tempTableName = entity.getTable() + "_temp";
//表重命名
db.execsql("ALTER TABLE " + entity.getTable() + " RENAME TO " + tempTableName);
//创建表
String sql = getCreatTablesql(clazz);
db.execsql(sql);
//旧数据转移
db.execsql("INSERT INTO "+entity.getTable()+"("+columns+") SELECT "+columns+" FROM "+tempTableName);
//删除临时表
db.execsql("DROP TABLE "+tempTableName);
}
}
}else{
//删除
db.execsql("DROP TABLE " + entity.getTable());
//创建表
String sql = getCreatTablesql(clazz);
db.execsql(sql);
}
}else{
//创建表
String sql = getCreatTablesql(clazz);
db.execsql(sql);
}
entity.setChecked(true);
}
4、本框架没有链表查询功能，int、Integer、long、Long、float、Float、double、Double、Boolean、String、Date以外字段利用GSON中的 Gson .toJson( Object src, Type typeOfSrc)获得json数据插入数据库，读取使用 .fromJson( String json,sans-serif; font-size:14px; line-height:21px">typeOfT)获得相应对象，具体看DEMO
/**
* 获取属性
* @param o
* @param info
* @return
*/
public static Object getProperty(Object o,ColumnInfo info){
try {
if(info.isBean()){
Field f = info.getField();
f.setAccessible(true);
Object value = f.get(o);
Gson gson = new GsonBuilder().create();
return gson.toJson(value,f.getGenericType());
}else{
Field f = info.getField();
f.setAccessible(true);
return f.get(o);
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 添加屬性
* @param o
* @param info
* @param value
*/
public static void setProperty(Object o,ColumnInfo info,Object value){
try {
if(info.isBean()){
Field f = info.getField();
Gson gson = new GsonBuilder().create();
Object obj = gson.fromJson((String) value,f.getGenericType());
f.setAccessible(true);
f.set(o,obj);
}else{
Field f = info.getField();
f.setAccessible(true);
f.set(o,value);
}
} catch (Exception e) {
e.printStackTrace();
}
}
原文链接：https://www.f2er.com/sqlite/200496.html
