Oracle数据库BLOB字段转换成inputStream输入流然后转换成字符串，然后从字符串转换成流输出到指定目录（Weblogic JMS传递）

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工具类：流转字符串工具类

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.servlet.http.HttpServletResponse;

import oracle.sql.BLOB;
 
/***
 * description: 对流数据的操作 
 */
public class ReadIo2Str {
 
	private static ReadIo2Str instance;
 
	private ReadIo2Str() {
	}
 
	public static ReadIo2Str getInstance() {
		if (null == instance) {
			instance = new ReadIo2Str();
		}
		return instance;
	}
 
	public static void main(String[] args) {
		String filePath = "D:\\1111\\111.docx";
		String filePath2 = "D:\\1111\\222.docx";
		String str = ReadIo2Str.getInstance().read2String(filePath);
		//ReadIo2Str.getInstance().read2Io(str, filePath2);
		System.out.println(str);
	}
 
	/**
	 * description:  将流转换成String
	 * @param filePath
	 * @return  
	 * @author xyc 
	 * @update 2015-6-4
	 */
	public String read2String(String filePath) {
		String ioStr = "";
		FileInputStream is = null;
		try {
			is = new FileInputStream(filePath);
			byte[] in = new byte[is.available()];
			is.read(in);
			ioStr = HQCodec.hexEncode(in);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (null != is) {
				try {
					is.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return ioStr;
	}
 
	/**
	 * description:  将文件流写到某一个目录下
	 * @param ioStr
	 * @param filePath  
	 * @author xyc 
	 * @update 2015-6-4
	 */
	public void read2Io(String ioStr, String filePath,String fileName) {
		FileOutputStream fos = null;
		try {
			byte[] iobyte = HQCodec.hexDecode(ioStr);
			File file = new File(filePath+fileName);
			if (file.exists()) {
				file.delete();
			}
			fos = new FileOutputStream(file);
			fos.write(iobyte, 0, iobyte.length);
			fos.flush();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (null != fos) {
				try {
					fos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
	
	
	/**
	 * description:  将Oracle数据库字段Blob转换成Input输入流然后转换成String
	 * @param filePath
	 * @return  
	 * @author xyc 
	 * @update 2015-6-4
	 */
	public String readStream2String(InputStream inputStream,byte[] bt) {
		String ioStr = "";
		InputStream is = inputStream;
		try {
			
			byte[] in = bt;
			is.read(in);
			ioStr = HQCodec.hexEncode(in);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (null != is) {
				try {
					is.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return ioStr;
	}
	
	public byte[] blobToBytes(BLOB blob) {
 		InputStream is = null;
 		byte[] b = null;
 		try {
 			is = blob.getBinaryStream();
 			b = new byte[(int) blob.length()];
 			is.read(b);
 			return b;
 		} catch (Exception e) {
 			e.printStackTrace();
 		} finally {
 			try {
 				is.close();
 				is = null;
 			} catch (IOException e) {
 				e.printStackTrace();
 			}
 		}
 		return b;
 	}
	
	/**
	 * description:  将文件流写到某一个目录下,并提供对外下载接口
	 * @param ioStr
	 * @param filePath  
	 * @author xyc 
	 * @update 2015-6-4
	 */
	public void read2IoRS(String ioStr, String filePath,String fileName,HttpServletResponse response) {
		FileOutputStream fos = null;
		try {
			byte[] iobyte = HQCodec.hexDecode(ioStr);
			File file = new File(filePath+fileName);
			if (file.exists()) {
				file.delete();
			}
			fos = new FileOutputStream(file);
			fos.write(iobyte, 0, iobyte.length);
			fos.flush();
			
			/**对外提供下载链接*/
			/*Path fileXZ = Paths.get(filePath, fileName);
			
			if (Files.exists(fileXZ)) {
	            response.setContentType("application/x-all");//ZIP压缩格式文件
	            try {
	                response.addHeader("Content-Disposition", "attachment; filename=" + URLEncoder.encode(fileName, "GBK"));
	                Files.copy(fileXZ, response.getOutputStream());
	            } catch (IOException ex) {
	                ex.printStackTrace();
	            }
	        }*/
			
			String filedl = filePath + fileName;
			
			download(filedl,response);
			
			
			/**对外提供下载链接结束*/
			
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (null != fos) {
				try {
					fos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
	
	
	 public HttpServletResponse download(String path, HttpServletResponse response) {
	        try {
	            // path是指欲下载的文件的路径。
	            File file = new File(path);
	            // 取得文件名。
	            String filename = file.getName();
	            // 取得文件的后缀名。
	            String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();

	            // 以流的形式下载文件。
	            InputStream fis = new BufferedInputStream(new FileInputStream(path));
	            byte[] buffer = new byte[fis.available()];
	            fis.read(buffer);
	            fis.close();
	            // 清空response
	            response.reset();
	            // 设置response的Header
	            response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes()));
	            response.addHeader("Content-Length", "" + file.length());
	            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
	            response.setContentType("application/octet-stream");
	            
	            toClient.write(buffer);
	            toClient.flush();
	            toClient.close();
	        } catch (IOException ex) {
	            ex.printStackTrace();
	        }
	        return response;
	    }
}

/**
 * description:  hexcode转换
 */
public class HQCodec {
 
	static final char[] HEX = new char[] { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E',
			'F' };
 
	public static String hexEncode(byte[] buffer) {
		if (buffer.length == 0) {
			return "";
		}
		int holder = 0;
		char[] chars = new char[buffer.length * 2];
		for (int i = 0; i < buffer.length; i++) {
			holder = (buffer[i] & 0xf0) >> 4;
			chars[i * 2] = HEX[holder];
			holder = buffer[i] & 0x0f;
			chars[(i * 2) + 1] = HEX[holder];
		}
		return new String(chars);
	}
 
	public static byte[] hexDecode(String hex) {
		//A null string returns an empty array
		if (hex == null || hex.length() == 0) {
			return new byte[0];
		} else if (hex.length() < 3) {
			return new byte[] { (byte) (Integer.parseInt(hex, 16) & 0xff) };
		}
		//Adjust accordingly for odd-length strings
		int count = hex.length();
		int nibble = 0;
		if (count % 2 != 0) {
			count++;
			nibble = 1;
		}
		byte[] buf = new byte[count / 2];
		char c = 0;
		int holder = 0;
		int pos = 0;
		for (int i = 0; i < buf.length; i++) {
			for (int z = 0; z < 2 && pos < hex.length(); z++) {
				c = hex.charAt(pos++);
				if (c >= 'A' && c <= 'F') {
					c -= 55;
				} else if (c >= '0' && c <= '9') {
					c -= 48;
				} else if (c >= 'a' && c <= 'f') {
					c -= 87;
				}
				if (nibble == 0) {
					holder = c << 4;
				} else {
					holder |= c;
					buf[i] = (byte) holder;
				}
				nibble = 1 - nibble;
			}
		}
		return buf;
	}
 
}

DAO层，BLOB转流然后转字符串

Map<String, Object> map = new HashMap<String, Object>();
					
BLOB blob = (BLOB) rs.getBlob("fjnr");
					
InputStream inputStream =  blob.getBinaryStream();
					
byte[] bt = ReadIo2Str.getInstance().blobToBytes(blob);
					
System.out.println("字节数组："+ bt);
					
String str1 = ReadIo2Str.getInstance().readStream2String(inputStream,bt);//转成String字符串
					
map.put("wj1", str1);

Controller获得BLOB转流转字符串之后的str1，然后将str1转成文件流输出

String filePath2 = "/home/fjlc/";//指定附件保存的位置
		
fileName = RW_BH + fileName;//附件的名称
		
ReadIo2Str.getInstance().read2IoRS(wjcontent, filePath2,fileName,response);//将wjcontent字符串转成流输出成文件并提供下载
		
//ReadIo2Str.getInstance().read2Io(wjcontent, filePath2,fileName);//附件内容保存

具体根据自己实际需要进行修改。