实现Mini版本的Mybatis
Model
public class TestModel {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "TestModel{" +
"name='" + name + '\'' +
'}';
}
}
Mapper接口与实现类
public interface TestMapper {
public TestModel getTestModel(Integer id);
}
public class TestMapperXml {
public static final Map<String,String> map=new HashMap<String,String>();
static{
//模拟xml中的id与sql语句
map.put("getTestModel", "测试SQL");
}
}
Executor接口与实现类
public interface TestExecutor {
public <T> T query(String statement,Object parameter);
}
public class TestSimpleExcutor implements TestExecutor{
public <T> T query(String statement, Object parameter) {
//JDBC 内容
TestModel model = new TestModel();
model.setName(statement + "-入参-" + parameter.toString());
return (T) model;
}
}
Handler实现类
public class TestMapperHandler implements InvocationHandler {
private TestSqlSession testSqlSession;
public TestMapperHandler(TestSqlSession testSqlSession) {
this.testSqlSession = testSqlSession;
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
return testSqlSession.selectOne(TestMapperXml.map.get(method.getName()),args[0]);
}
}
SqlSession实现类
public class TestSqlSession {
private TestExecutor excutor = new TestSimpleExcutor();
public <T> T selectOne(String statement,Object parameter){
return excutor.query(statement, parameter);
}
public <T> T getMapper(Class<T> clas){
return (T) Proxy.newProxyInstance(clas.getClassLoader(),new Class[]{clas}, new TestMapperHandler(this));
}
}
调用类
public class TestMainMybatis {
public static void main(String[] args) {
TestSqlSession sqlsession = new TestSqlSession();
TestMapper mapper = sqlsession.getMapper(TestMapper.class);
TestModel model = mapper.getTestModel(1);
System.out.println(model.toString());
}
}
