Spring让LOB数据操作变得简单易行

package com.baobaotao.dao.jdbc; 
… 
import java.sql.PreparedStatement; 
import java.sql.SQLException; 
import org.springframework.jdbc.core.support.AbstractLobCreatingPreparedStatementCallback; 
import org.springframework.jdbc.support.lob.LobCreator; 
import org.springframework.jdbc.support.lob.LobHandler; 

public class PostJdbcDao extends JdbcDaoSupport implements PostDao { 
  private LobHandler lobHandler; ① 定义 LobHandler 属性 
  public LobHandler getLobHandler() { 
    return lobHandler; 
  } 
  public void setLobHandler(LobHandler lobHandler) { 
    this.lobHandler = lobHandler; 
  } 
  public void addPost(final Post post) {     
    String sql = " INSERT INTO t_post(post_id,user_id,post_text,post_attach)" 
        + " VALUES(?,?,?,?)"; 
    getJdbcTemplate().execute(sql, 
      new AbstractLobCreatingPreparedStatementCallback(this.lobHandler) { ② 
          protected void setValues(PreparedStatement ps,LobCreator lobCreator) 
                      throws SQLException { 
            ps.setInt(1, 1);   
            ps.setInt(2, post.getUserId());   
            ③ 设置 CLOB 字段 
            lobCreator.setClobAsString(ps, 3, post.getPostText()); 
            ④ 设置 BLOB 字段 
            lobCreator.setBlobAsBytes(ps, 4, post.getPostAttach()); 
          } 
        }); 
  } 
… 
} 

… 
＜bean id="nativeJdbcExtractor"  
class="org.springframework.jdbc.support.nativejdbc.CommonsDbcpNativeJdbcExtractor" 
lazy-init="true"/＞ 
＜bean id="oracleLobHandler"  
class="org.springframework.jdbc.support.lob.OracleLobHandler"  
lazy-init="true"＞ 
   ＜property name="nativeJdbcExtractor" ref="nativeJdbcExtractor"/＞ ① 设置本地 Jdbc 对象抽取器 
＜/bean＞ 
＜bean id="postDao" class="com.baobaotao.dao.jdbc.PostJdbcDao"＞ 
   ＜property name="lobHandler" ref="oracleLobHandler"/＞ ② 设置 LOB 处理器 
＜/bean＞ 

＜bean id="defaultLobHandler"  
class="org.springframework.jdbc.support.lob.DefaultLobHandler"  
lazy-init="true"/＞ 
＜bean id="postDao" class="com.baobaotao.dao.jdbc.PostJdbcDao"＞ 
   ＜property name="lobHandler" ref=" defaultLobHandler"/＞  
＜property name="jdbcTemplate" ref="jdbcTemplate" /＞ 
＜/bean＞ 
 

package com.baobaotao.dao.jdbc; 

import org.springframework.core.io.ClassPathResource; 
import org.springframework.test.AbstractDependencyInjectionSpringContextTests; 
import org.springframework.util.FileCopyUtils; 
import com.baobaotao.dao.PostDao; 
import com.baobaotao.domain.Post; 
public class TestPostJdbcDaoextends AbstractDependencyInjectionSpringContextTests { 
  private PostDao postDao; 
  public void setPostDao(PostDao postDao) { 
    this.postDao = postDao; 
  } 
  protected String[] getConfigLocations() { 
    return new String[]{"classpath:applicationContext.xml"}; 
  } 
  public void testAddPost() throws Throwable{ 
    Post post = new Post(); 
    post.setPostId(1); 
    post.setUserId(2); 
    ClassPathResource res = new ClassPathResource("temp.jpg"); ① 获取图片资源 
    byte[] mockImg = FileCopyUtils.copyToByteArray(res.getFile());  ② 读取图片文件的数据 
    post.setPostAttach(mockImg); 
    post.setPostText("测试帖子的内容"); 
    postDao.addPost(post); 
  } 
}