Android基于Java反射机制的简单ORM-Dao层

无需配置，但需要按照一定的规则写POJO。规则：①基础类型只能使用short,int,long,float,double,String。②表名需与类名相同。③表的属性名需与类成员变量名相同。④每个类都需要有一个基础类型的id成员变量。⑤对象之间可以嵌套存取，但不要出现循环嵌套循环嵌套如下： public class Fruit {     private Apple apple; } public class Apple {     private Fruit fruit; }⑥成员变量中可以为 基础类型 已成表的对象类型 已成表的对象类型的容器（只支持ArrayList）//存储对象，对象已存在抛出异常public void save(Object object, SQLiteDatabase db) throws Exception {    Class clazz = object.getClass();    Field[] fields = clazz.getDeclaredFields();    ContentValues contentValues = new ContentValues();    Object id = null;    for(Field field : fields) {        if(field.getName().equals("id")) {            String methodName = createGetMethodName(field.getName());            Method method = clazz.getMethod(methodName);            id = method.invoke(object);            break;        }    }    try {        if (id == null) throw new Exception();    } catch (Exception e) {        e.printStackTrace();    }    for(Field field : fields) {        Class filedClazz = field.getType();        String methodName = createGetMethodName(field.getName());        Method method = clazz.getMethod(methodName);        Object filedObject = method.invoke(object);        if(filedObject == null) continue;        if(isBaseDataType(filedClazz)) {            Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(filedObject.getClass()));            putMethod.invoke(contentValues, field.getName(), filedObject);        } else if(Collection.class.isAssignableFrom(filedClazz)) {            Collection collection = (Collection) filedObject;            Iterator iterator = collection.iterator();            while(iterator.hasNext()) {                ContentValues contentValues2 = new ContentValues();                Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(id.getClass()));                putMethod.invoke(contentValues2, getSimpleName(clazz.getName()), id);                Object object2 = iterator.next();                saveOrUpdate(object2, db, contentValues2);            }        } else {            String filedMethodName = "getId";            Method filedMethod = filedClazz.getMethod(filedMethodName);            Object filedFiledObject = filedMethod.invoke(filedObject);            Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(filedFiledObject.getClass()));            putMethod.invoke(contentValues, field.getName(), filedFiledObject);            saveOrUpdate(filedObject, db);        }    }    String tableName = getSimpleName(clazz.getName());    Cursor cursor = db.query(tableName ,null,"id=?", new String[] {String.valueOf(contentValues.get("id"))}, null, null, null);    if(!cursor.moveToFirst())        db.insert(tableName, null, contentValues);    cursor.close();}//保存对象，对象已存在则更新对象public void saveOrUpdate(Object object, SQLiteDatabase db) throws Exception {    Class clazz = object.getClass();    Field[] fields = clazz.getDeclaredFields();    ContentValues contentValues = new ContentValues();    Object id = null;    for(Field field : fields) {        if(field.getName().equals("id")) {            String methodName = createGetMethodName(field.getName());            Method method = clazz.getMethod(methodName);            id = method.invoke(object);            break;        }    }    try {        if (id == null) throw new Exception();    } catch (Exception e) {        e.printStackTrace();    }    for(Field field : fields) {        Class filedClazz = field.getType();        String methodName = createGetMethodName(field.getName());        Method method = clazz.getMethod(methodName);        Object filedObject = method.invoke(object);        if(filedObject == null) continue;        if(isBaseDataType(filedClazz)) {            Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(filedObject.getClass()));            putMethod.invoke(contentValues, field.getName(), filedObject);        } else if(Collection.class.isAssignableFrom(filedClazz)) {            Collection collection = (Collection) filedObject;            Iterator iterator = collection.iterator();            while(iterator.hasNext()) {                ContentValues contentValues2 = new ContentValues();                Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(id.getClass()));                putMethod.invoke(contentValues2, getSimpleName(clazz.getName()), id);                Object object2 = iterator.next();                saveOrUpdate(object2, db, contentValues2);            }        } else {            String filedMethodName = "getId";            Method filedMethod = filedClazz.getMethod(filedMethodName);            Object filedFiledObject = filedMethod.invoke(filedObject);            Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(filedFiledObject.getClass()));            putMethod.invoke(contentValues, field.getName(), filedFiledObject);            saveOrUpdate(filedObject, db);        }    }    String tableName = getSimpleName(clazz.getName());    Cursor cursor = db.query(tableName ,null,"id=?", new String[] {String.valueOf(contentValues.get("id"))}, null, null, null);    if(!cursor.moveToFirst())        db.insert(tableName, null, contentValues);    else db.update(tableName, contentValues, "id=?", new String[] {String.valueOf(contentValues.get("id"))});    cursor.close();}//配合上一个方法使用public void saveOrUpdate(Object object, SQLiteDatabase db, ContentValues contentValues) throws Exception {    Class clazz = object.getClass();    Field[] fields = clazz.getDeclaredFields();    Object id = null;    for(Field field : fields) {        if(field.getName().equals("id")) {            String methodName = createGetMethodName(field.getName());            Method method = clazz.getMethod(methodName);            id = method.invoke(object);            break;        }    }    try {        if (id == null) throw new Exception();    } catch (Exception e) {        e.printStackTrace();    }    for(Field field : fields) {        Class filedClazz = field.getType();        String methodName = createGetMethodName(field.getName());        Method method = clazz.getMethod(methodName);        Object filedObject = method.invoke(object);        if(filedObject == null) continue;        if(isBaseDataType(filedClazz)) {            Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(filedObject.getClass()));            putMethod.invoke(contentValues, field.getName(), filedObject);        } else if(Collection.class.isAssignableFrom(filedClazz)) {            Collection collection = (Collection) filedObject;            Iterator iterator = collection.iterator();            while(iterator.hasNext()) {                ContentValues contentValues2 = new ContentValues();                Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(id.getClass()));                putMethod.invoke(contentValues2, getSimpleName(clazz.getName()), id);                Object object2 = iterator.next();                saveOrUpdate(object2, db, contentValues2);            }        } else {            String filedMethodName = "getId";            Method filedMethod = filedClazz.getMethod(filedMethodName);            Object filedFiledObject = filedMethod.invoke(filedObject);            Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(filedFiledObject.getClass()));            putMethod.invoke(contentValues, field.getName(), filedFiledObject);            saveOrUpdate(filedObject, db);        }    }    String tableName = getSimpleName(clazz.getName());    Cursor cursor = db.query(tableName ,null,"id=?", new String[] {String.valueOf(contentValues.get("id"))}, null, null, null);    if(!cursor.moveToFirst())        db.insert(tableName, null, contentValues);    else db.update(tableName, contentValues, "id=?", new String[] {String.valueOf(contentValues.get("id"))});    cursor.close();}//更新对象，对象不存在则抛出异常public void update(Object object, SQLiteDatabase db) throws Exception {    Class clazz = object.getClass();    Field[] fields = clazz.getDeclaredFields();    ContentValues contentValues = new ContentValues();    Object id = null;    for(Field field : fields) {        if(field.getName().equals("id")) {            String methodName = createGetMethodName(field.getName());            Method method = clazz.getMethod(methodName);            id = method.invoke(object);            break;        }    }    try {        if (id == null) throw new Exception();    } catch (Exception e) {        e.printStackTrace();    }    for(Field field : fields) {        Class filedClazz = field.getType();        String methodName = createGetMethodName(field.getName());        Method method = clazz.getMethod(methodName);        Object filedObject = method.invoke(object);        if(filedObject == null) continue;        if(isBaseDataType(filedClazz)) {            Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(filedObject.getClass()));            putMethod.invoke(contentValues, field.getName(), filedObject);        } else if(Collection.class.isAssignableFrom(filedClazz)) {            Collection collection = (Collection) filedObject;            Iterator iterator = collection.iterator();            while(iterator.hasNext()) {                ContentValues contentValues2 = new ContentValues();                Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(id.getClass()));                putMethod.invoke(contentValues2, getSimpleName(clazz.getName()), id);                Object object2 = iterator.next();                saveOrUpdate(object2, db, contentValues2);            }        } else {            String filedMethodName = "getId";            Method filedMethod = filedClazz.getMethod(filedMethodName);            Object filedFiledObject = filedMethod.invoke(filedObject);            Method putMethod = ContentValues.class.getMethod("put", String.class, toObjectClass(filedFiledObject.getClass()));            putMethod.invoke(contentValues, field.getName(), filedFiledObject);            saveOrUpdate(filedObject, db);        }    }    String tableName = getSimpleName(clazz.getName());    Cursor cursor = db.query(tableName ,null,"id=?", new String[] {String.valueOf(contentValues.get("id"))}, null, null, null);    if(cursor.moveToFirst())        db.update(tableName, contentValues, "id=?", new String[] {String.valueOf(contentValues.get("id"))});    else throw new Exception();    cursor.close();}//根据id取对象public Object get(Class clazz, Object id, SQLiteDatabase db) throws Exception {    Cursor cursor = db.rawQuery("select * from " + getSimpleName(clazz.getName()) + " where id=?", new String[]{String.valueOf(id)});    if(cursor.moveToFirst()) {        Constructor constructor = clazz.getConstructor();        Object object = constructor.newInstance();        Field[] fields = clazz.getDeclaredFields();        for(Field field : fields) {            Log.d("sss", field.getName());            String methodName = createSetMethodName(field.getName());            Method method = clazz.getMethod(methodName, field.getType());            Class cs2 = field.getType();            Class cursorType = null;            if(isBaseDataType(field.getType())) {                cursorType = field.getType();                String cusorTypeName = getSimpleName(toBaseClass(cursorType).toString());                String cursorMethodName = createGetMethodName(cusorTypeName);                Method cursorMethod = Cursor.class.getMethod(cursorMethodName, int.class);                Object cursorResult = cursorMethod.invoke(cursor, cursor.getColumnIndex(field.getName()));                method.invoke(object, cursorResult);            } else if(Collection.class.isAssignableFrom(field.getType())) {                String name = getSingleName(field.getName());                Collection collection = new ArrayList();                collection.addAll(list(Class.forName(getClassName(name)), db, "select * from " + name + " where " + getSimpleName(clazz.getName()) + "=?", new String[]{String.valueOf(id)}));                method.invoke(object, collection);            } else {                cursorType = field.getType().getDeclaredField("id").getType();                String cusorTypeName = getSimpleName(toBaseClass(cursorType).toString());                String cursorMethodName = createGetMethodName(cusorTypeName);                Method cursorMethod = Cursor.class.getMethod(cursorMethodName, int.class);                Object cursorResult = cursorMethod.invoke(cursor, cursor.getColumnIndex(field.getName()));                method.invoke(object, get(field.getType(), cursorResult, db));            }        }        cursor.close();        return object;    }    cursor.close();    return null;}//根据sql语句取对象public Object get(Class clazz, SQLiteDatabase db, String sql, String... strings) throws Exception {    Cursor cursor = db.rawQuery(sql, strings);    if(cursor.moveToFirst()) {        Constructor constructor = clazz.getConstructor();        Object object = constructor.newInstance();        Field[] fields = clazz.getDeclaredFields();        Object id = null;        for(Field field : fields) {            if(field.getName().equals("id")) {                String cusorTypeName = getSimpleName(toBaseClass(field.getType()).toString());                String cursorMethodName = createGetMethodName(cusorTypeName);                Method cursorMethod = Cursor.class.getMethod(cursorMethodName, int.class);                id = cursorMethod.invoke(cursor, cursor.getColumnIndex(field.getName()));                break;            }        }        for(Field field : fields) {            Log.d("sss", field.getName());            String methodName = createSetMethodName(field.getName());            Method method = clazz.getMethod(methodName, field.getType());            Class cursorType = null;            if(isBaseDataType(field.getType())) {                cursorType = field.getType();                String cusorTypeName = getSimpleName(toBaseClass(cursorType).toString());                String cursorMethodName = createGetMethodName(cusorTypeName);                Method cursorMethod = Cursor.class.getMethod(cursorMethodName, int.class);                Object cursorResult = cursorMethod.invoke(cursor, cursor.getColumnIndex(field.getName()));                method.invoke(object, cursorResult);            } else if(Collection.class.isAssignableFrom(field.getClass())) {                String name = getSingleName(field.getName());                Collection collection = new ArrayList();                collection.addAll(list(Class.forName(getClassName(name)), db, "select * from " + name + " where " + getSimpleName(clazz.getName()) + "=?", new String[]{String.valueOf(id)}));                method.invoke(object, collection);            } else {                cursorType = field.getType().getDeclaredField("id").getType();                String cusorTypeName = getSimpleName(toBaseClass(cursorType).toString());                String cursorMethodName = createGetMethodName(cusorTypeName);                Method cursorMethod = Cursor.class.getMethod(cursorMethodName, int.class);                Object cursorResult = cursorMethod.invoke(cursor, cursor.getColumnIndex(field.getName()));                method.invoke(object, get(field.getType(), cursorResult, db));            }        }        cursor.close();        return object;    }    cursor.close();    return null;}//根据sql取多个对象public List list(Class clazz, SQLiteDatabase db, String sql, String... strings) throws Exception {    Cursor cursor = db.rawQuery(sql, strings);    List list = new ArrayList();    while(cursor.moveToNext()) {        Constructor constructor = clazz.getConstructor();        Object object = constructor.newInstance();        Field[] fields = clazz.getDeclaredFields();        Object id = null;        for(Field field : fields) {            if(field.getName().equals("id")) {                String cusorTypeName = getSimpleName(toBaseClass(field.getType()).toString());                String cursorMethodName = createGetMethodName(cusorTypeName);                Method cursorMethod = Cursor.class.getMethod(cursorMethodName, int.class);                id = cursorMethod.invoke(cursor, cursor.getColumnIndex(field.getName()));                break;            }        }        for(Field field : fields) {            Log.d("sss", field.getName());            String methodName = createSetMethodName(field.getName());            Method method = clazz.getMethod(methodName, field.getType());            Class cursorType = null;            if(isBaseDataType(field.getType())) {                cursorType = field.getType();                String cusorTypeName = getSimpleName(toBaseClass(cursorType).toString());                String cursorMethodName = createGetMethodName(cusorTypeName);                Method cursorMethod = Cursor.class.getMethod(cursorMethodName, int.class);                Object cursorResult = cursorMethod.invoke(cursor, cursor.getColumnIndex(field.getName()));                method.invoke(object, cursorResult);            } else if(Collection.class.isAssignableFrom(field.getClass())) {                String name = getSingleName(field.getName());                Collection collection = new ArrayList();                collection.addAll(list(Class.forName(getClassName(name)), db, "select * from " + name + " where " + getSimpleName(clazz.getName()) + "=?", new String[]{String.valueOf(id)}));                method.invoke(object, collection);            } else {                cursorType = field.getType().getDeclaredField("id").getType();                String cusorTypeName = getSimpleName(toBaseClass(cursorType).toString());                String cursorMethodName = createGetMethodName(cusorTypeName);                Method cursorMethod = Cursor.class.getMethod(cursorMethodName, int.class);                Object cursorResult = cursorMethod.invoke(cursor, cursor.getColumnIndex(field.getName()));                method.invoke(object, get(field.getType(), cursorResult, db));            }        }        list.add(object);    }    cursor.close();    return list;}private String getClassName(String name) {    char[] chars = name.toCharArray();    if(Character.isLowerCase(chars[0]))        chars[0] -= 32;    name = "com.example.administrator.share.model." + String.valueOf(chars);    return name;}private String getSingleName(String name) {    return name.substring(0, name.length() - 1);}private String createGetMethodName(String name) {    String methodName = "get" + name;    char[] chars = methodName.toCharArray();    if(Character.isLowerCase(chars[3]))        chars[3] -= 32;    return String.valueOf(chars);}private String createSetMethodName(String name) {    String methodName = "set" + name;    char[] chars = methodName.toCharArray();    if(Character.isLowerCase(chars[3]))        chars[3] -= 32;    return String.valueOf(chars);}private String getSimpleName(String name) {    String[] strings = name.split("\\.");    return strings[strings.length - 1];}private Class toBaseClass(Class clazz) {    if(clazz.equals(Integer.class)) return int.class;    if(clazz.equals(Short.class)) return short.class;    if(clazz.equals(Byte.class)) return byte.class;    if(clazz.equals(Long.class)) return long.class;    if(clazz.equals(Double.class)) return double.class;    if(clazz.equals(Float.class)) return float.class;    if(clazz.equals(Character.class)) return char.class;    if(clazz.equals(Boolean.class)) return boolean.class;    return clazz;}private Class toObjectClass(Class clazz) {    if(clazz.equals(int.class)) return Integer.class;    if(clazz.equals(short.class)) return Short.class;    if(clazz.equals(byte.class)) return Byte.class;    if(clazz.equals(long.class)) return Long.class;    if(clazz.equals(double.class)) return Double.class;    if(clazz.equals(float.class)) return Float.class;    if(clazz.equals(char.class)) return Character.class;    if(clazz.equals(boolean.class)) return Boolean.class;    return clazz;}private boolean isBaseDataType(Class clazz) {    return (clazz.equals(String.class) || clazz.equals(Integer.class) || clazz.equals(Byte.class)            || clazz.equals(Long.class) || clazz.equals(Double.class) || clazz.equals(Float.class)            || clazz.equals(Character.class) || clazz.equals(Short.class) || clazz.equals(Boolean.class)            || clazz.isPrimitive());}