Spring JdbcTemplate 应用(三)

在这篇文章里介绍用JdbcTemplate进行数据库插入操作，包括对blob或clob字段的插入


还有对blob字段的取出操作。


1.使用JdbcTemplate往数据库里插入数据，其中包含blob字段。

public boolean doSubmitWeekly(final WeeklyVO weeklyVO)
			throws DataAccessException {
		StringBuffer sql = new StringBuffer();
		sql.append("INSERT INTO WEEKLY_INFO_T T (T.F_START_TIME, ");
		sql.append("                                 T.F_END_TIME, ");
		sql.append("                                 T.F_DATE, ");
		sql.append("                                 T.F_OWNER, ");
		sql.append("                                 T.F_ANNEX_NAME, ");
		sql.append("                                 T.F_ANNEX) ");
		sql.append("  VALUES   (TO_DATE (?, 'yyyy-mm-dd'), ");
		sql.append("            TO_DATE (?, 'yyyy-mm-dd'), ");
		sql.append("            TO_DATE (to_char(sysdate,'yyyy-mm-dd'), 'yyyy-mm-dd'), ");
		sql.append("            ?, ");
		sql.append("            ?, ");
		sql.append("            ?) ");//blob字段

		Boolean flag = new Boolean(false);

		try {
			flag = (Boolean) this.getJdbcTemplate().execute(sql.toString(),
					new MyPreparedStatementCallback(weeklyVO));
		} catch (Exception e) {
			e.printStackTrace();
		}
		return flag.booleanValue();
	}

MyPreparedStatementCallback类的实现

/**
 * 上传附件回调操作类
 */
private class MyPreparedStatementCallback implements
		PreparedStatementCallback {

	private WeeklyVO weeklyVO;

	public MyPreparedStatementCallback(WeeklyVO weeklyVO) {
		this.weeklyVO = weeklyVO;
	}

	public Object doInPreparedStatement(PreparedStatement pstm)
			throws SQLException,
			org.springframework.dao.DataAccessException {

		pstm.setObject(1, this.weeklyVO.getStartTime());
		pstm.setObject(2, this.weeklyVO.getEndTime());
		pstm.setObject(3, this.weeklyVO.getOwner());
		pstm.setObject(4, this.weeklyVO.getAnnexName());
		try {
			// 操作Blob ---这里WeeklyVO类的annex属性是File类型
			pstm.setBinaryStream(5, new FileInputStream(this.weeklyVO
							.getAnnex()), (int) (this.weeklyVO.getAnnex()).length());
			// 操作Clob
			/**
			pstm.setCharacterStream(5, new FileReader(this.weeklyVO
							.getAnnex()), (int) (this.weeklyVO.getAnnex()).length());
			*/
		} catch (FileNotFoundException e) {
			e.printStackTrace();
			return new Boolean(false);
		}

		try {
			pstm.execute();
			return new Boolean(true);
		} catch (Exception e) {
			e.printStackTrace();
			return new Boolean(false);
		}
	}

}

2.使用JdbcTemplate读取数据库中的blob字段信息(把blob内容写到临时目录)

public Map doSelectWeekly(String weeklyId) throws DataAccessException {
		String sql = "select t.f_annex_name,t.f_annex from weekly_info_t t"
				+ " where t.f_weekly_id = " + weeklyId;
		Map map = new HashMap();
		map = (Map) this.getJdbcTemplate().execute(sql,
				new CallableStatementCallback() {

					public Object doInCallableStatement(CallableStatement stmt)
							throws SQLException,
							org.springframework.dao.DataAccessException {
						ResultSet rs = stmt.executeQuery();
						Map map = new HashMap();
						InputStream inputStream = null;
						String name = "";
						String path = System.getProperty("java.io.tmpdir")
								+ "/";
						File temp = new File(path);
						if (!temp.exists()) {
							temp.mkdir();
						}
						temp = null;

						while (rs.next()) {
							inputStream = rs.getBinaryStream("f_annex");// 读取blob

                    //Reader fileReader = rs.getCharacterStream("f_annex");// 读取clob
							name = rs.getString("f_annex_name");
							path += name;
							File fileOutput = new File(path);

							FileOutputStream fo;
							try {
								fo = new FileOutputStream(fileOutput);
								int readed;
								// 将附件写到临时目录里
								while ((readed = inputStream.read()) != -1) {
									fo.write(readed);
								}
								fo.close();
							} catch (FileNotFoundException e) {
								e.printStackTrace();
							} catch (IOException e) {
								e.printStackTrace();
							}
						}
						map.put("annexName", name);
						map.put("filePath", path);
						return map;//返回文件名称和文件所在路径，供页面下载用。
					}

				});
		return map;
	}

附：下载blob内容代码片段（先把blob内容写到临时目录在从临时目录下载）

Map map = weeklyServise.doSelectWeekly("52");//参数为附件ID
String annexName = (String) map.get("annexName");
String path = (String) map.get("filePath");

BufferedInputStream bis = null;
BufferedOutputStream bos = null;
OutputStream fos = null;
InputStream fis = null;

String filepath = path;
System.out.println("文件路径" + filepath);
java.io.File uploadFile = new java.io.File(filepath);
//从低级流构造成高级流
fis = new FileInputStream(uploadFile);
bis = new BufferedInputStream(fis);
fos = response.getOutputStream();
bos = new BufferedOutputStream(fos);
//设置下载文件名
response.setHeader("Content-disposition", "attachment;filename="
		+ URLEncoder.encode(annexName, "utf-8"));
int bytesRead = 0;
byte[] buffer = new byte[4096];
while ((bytesRead = bis.read(buffer, 0, 4096)) != -1) {
	bos.write(buffer, 0, bytesRead);//开始下载数据
}
bos.flush();
fis.close();
bis.close();
fos.close();
bos.close();
java.io.File temp = new java.io.File(System.getProperty("java.io.tmpdir")+"/");
if(temp.isDirectory()){
	FileUtils.deleteDirectory(temp);//删除临时文件夹
}
return null;