mybatis获取Oracle的Blob字段转成Base64编码

时间:2025-03-12 07:25:14

由于借鉴了其他获取Oracle数据库Blob方法,试了多次没有成功,自己磨了两个小时磨了出来,在这里记录下来,以便以后查阅!

这里使用的SpringBoot搭建的maven环境,只需将springboot的包引入即可,并且数据库中需要创建一张测试表,里面有Blob的字段,这里我建的表叫test表,且里面有个blob字段叫ZP

1.创建测试Mapper文件

这里返回的值为Map<Object,Object> 类型,即查询的Blob字段放入到Object类型中

@Mapper
public interface TestMapper {
	@Select("select zp from test")
	public List<Map<Object,Object>> getList();
}

2.创建测试service接口文件与实现文件

@Repository
public interface TestService {
	public List<Map<Object,Object>> getList();
}
@Repository
public class TestServiceImpl implements TestService {
	@Autowired
	TestMapper testMapper;
	public List<Map<Object, Object>> getList() {
		return ();
	}
}

转byte[]、Blob转文件、Blob转base64编码

  /**
	 * 测试方法
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
	   (, args);
	   List<Map<Object, Object>>  list = ().getList();
	   for (Map<Object, Object> map : list) {
		   BLOB blob = (BLOB)("ZP");  
		   (blobToBase64(blob));
		   blobToPic(blob);
	   }
	}
	
	
	/**
	 * blob转base64
	 * @param blob
	 * @throws Exception
	 */
	public static String blobToBase64(Blob blob) throws Exception{
		return Base64.encodeBase64String(blobToByte(blob));
	}
	
	/**
	 * blob转pic
	 * @param blob
	 * @throws Exception
	 */
	public static void blobToPic(Blob blob) throws Exception{
		byte[] bt = blobToByte(blob);
		FileImageOutputStream imageOutput = new FileImageOutputStream(new File("F:/"));
	    (bt, 0, );
	    ();
	}
	
	/**
	 * blob转byte
	 * @param blob
	 * @throws Exception
	 */
	public static byte[] blobToByte(Blob blob) throws Exception{
		InputStream is = (InputStream) blob .getBinaryStream();  
	    byte[] bs = new byte[1000];
	    int len = -1;
	    ByteArrayOutputStream os = new ByteArrayOutputStream(); 
	    while((len=(bs)) != -1){
		   (bs, 0, len);
	    }
	    byte[] bt = ();
	    ();
	    ();
	    return bt;
	}