Mybatis的SqlRunner执行流程

 Mybatis的SqlRunner执行流程

    SqlRunner exec = new SqlRunner(connection);    Map<String, Object> row = exec.selectOne("SELECT * FROM PRODUCT WHERE PRODUCTID = ?", "FI-SW-01");connection.close();assertEquals("FI-SW-01", row.get("PRODUCTID"));

TypeHandlerRegistry类中TYPE_HANDLER_MAP 的初始化过程

  public TypeHandlerRegistry() {//构造函数里注册系统内置的类型处理器//以下是为多个类型注册到同一个handlerregister(Boolean.class, new BooleanTypeHandler());register(boolean.class, new BooleanTypeHandler());register(JdbcType.BOOLEAN, new BooleanTypeHandler());register(JdbcType.BIT, new BooleanTypeHandler());register(Byte.class, new ByteTypeHandler());register(byte.class, new ByteTypeHandler());register(JdbcType.TINYINT, new ByteTypeHandler());register(Short.class, new ShortTypeHandler());register(short.class, new ShortTypeHandler());register(JdbcType.SMALLINT, new ShortTypeHandler());register(Integer.class, new IntegerTypeHandler());register(int.class, new IntegerTypeHandler());register(JdbcType.INTEGER, new IntegerTypeHandler());register(Long.class, new LongTypeHandler());register(long.class, new LongTypeHandler());register(Float.class, new FloatTypeHandler());register(float.class, new FloatTypeHandler());register(JdbcType.FLOAT, new FloatTypeHandler());register(Double.class, new DoubleTypeHandler());register(double.class, new DoubleTypeHandler());register(JdbcType.DOUBLE, new DoubleTypeHandler());//以下是为同一个类型的多种变种注册到多个不同的handlerregister(String.class, new StringTypeHandler());register(String.class, JdbcType.CHAR, new StringTypeHandler());register(String.class, JdbcType.CLOB, new ClobTypeHandler());register(String.class, JdbcType.VARCHAR, new StringTypeHandler());register(String.class, JdbcType.LONGVARCHAR, new ClobTypeHandler());register(String.class, JdbcType.NVARCHAR, new NStringTypeHandler());register(String.class, JdbcType.NCHAR, new NStringTypeHandler());register(String.class, JdbcType.NCLOB, new NClobTypeHandler());register(JdbcType.CHAR, new StringTypeHandler());register(JdbcType.VARCHAR, new StringTypeHandler());register(JdbcType.CLOB, new ClobTypeHandler());register(JdbcType.LONGVARCHAR, new ClobTypeHandler());register(JdbcType.NVARCHAR, new NStringTypeHandler());register(JdbcType.NCHAR, new NStringTypeHandler());register(JdbcType.NCLOB, new NClobTypeHandler());register(Object.class, JdbcType.ARRAY, new ArrayTypeHandler());register(JdbcType.ARRAY, new ArrayTypeHandler());register(BigInteger.class, new BigIntegerTypeHandler());register(JdbcType.BIGINT, new LongTypeHandler());register(BigDecimal.class, new BigDecimalTypeHandler());register(JdbcType.REAL, new BigDecimalTypeHandler());register(JdbcType.DECIMAL, new BigDecimalTypeHandler());register(JdbcType.NUMERIC, new BigDecimalTypeHandler());register(Byte[].class, new ByteObjectArrayTypeHandler());register(Byte[].class, JdbcType.BLOB, new BlobByteObjectArrayTypeHandler());register(Byte[].class, JdbcType.LONGVARBINARY, new BlobByteObjectArrayTypeHandler());register(byte[].class, new ByteArrayTypeHandler());register(byte[].class, JdbcType.BLOB, new BlobTypeHandler());register(byte[].class, JdbcType.LONGVARBINARY, new BlobTypeHandler());register(JdbcType.LONGVARBINARY, new BlobTypeHandler());register(JdbcType.BLOB, new BlobTypeHandler());register(Object.class, UNKNOWN_TYPE_HANDLER);register(Object.class, JdbcType.OTHER, UNKNOWN_TYPE_HANDLER);register(JdbcType.OTHER, UNKNOWN_TYPE_HANDLER);register(Date.class, new DateTypeHandler());register(Date.class, JdbcType.DATE, new DateOnlyTypeHandler());register(Date.class, JdbcType.TIME, new TimeOnlyTypeHandler());register(JdbcType.TIMESTAMP, new DateTypeHandler());register(JdbcType.DATE, new DateOnlyTypeHandler());register(JdbcType.TIME, new TimeOnlyTypeHandler());register(java.sql.Date.class, new SqlDateTypeHandler());register(java.sql.Time.class, new SqlTimeTypeHandler());register(java.sql.Timestamp.class, new SqlTimestampTypeHandler());// issue #273register(Character.class, new CharacterTypeHandler());register(char.class, new CharacterTypeHandler());}

回到流程中

 

 

 

 

原始的jdbc代码 

/*执行DQL语句
*/import java.sql.*;
import java.util.*;public class JDBCTest05 {public static void main(String[] args) {// 1、注册驱动// 2、建立连接// 3、获取数据库操作对象// 4、执行sql语句// 5、获取查询结果集// 6、释放资源Connection conn = null;Statement stmt = null;ResultSet rs = null;try{ResourceBundle rb = ResourceBundle.getBundle("jdbc");String driver = rb.getString("driver");String url = rb.getString("url");String user = rb.getString("user");String password = rb.getString("password");Class.forName(driver);conn = DriverManager.getConnection(url,user,password);stmt = conn.createStatement();rs = stmt.executeQuery("select empno,ename,sal from emp");while(rs.next()){/*String empno = rs.getString(1);String ename = rs.getString(2);String sal = rs.getString(3);System.out.println(empno + "," + ename + "," + sal);*//*// 按下标取出，程序不健壮String empno = rs.getString("empno");String ename = rs.getString("ename");String sal = rs.getString("sal");System.out.println(empno + "," + ename + "," + sal);*//*// 以指定的格式取出int empno = rs.getInt(1);String ename = rs.getString(2);double sal = rs.getDouble(3);System.out.println(empno + "," + ename + "," + (sal + 100));*/int empno = rs.getInt("empno");String ename = rs.getString("ename");double sal = rs.getDouble("sal");System.out.println(empno + "," + ename + "," + (sal + 200));}} catch(Exception e){e.printStackTrace();}finally{if(rs != null){try{rs.close();} catch (Exception e){e.printStackTrace();}}if(stmt != null){try{stmt.close();} catch (Exception e){e.printStackTrace();}}if(conn != null){try{conn.close();} catch (Exception e){e.printStackTrace();}}}}
}