文本数据增量导入到mysql

 实现思路：
       实现Java读取TXT文件中的内容并存到内存,将内存中的数据和mysql 数据库里面某张表数据的字段做一个比较，如果比较内存中的数据在mysql 里存在则不做处理，如果不存在则将该数据插入mysql数据库中

步骤1、读取文本数据   给一个string 返回值

步骤2、查询mysql 表中数据  给一个String 返回值

步骤3  、内存中文本数据和读取的mysql 数据做比较

/**
	 * 实现读取文件信息
	 * 
	 * @param fileName
	 * @return
	 */
	public static String readFileByLines(String fileName) {
		String result = "";
		file = new File(fileName);
		String tempString = null;
		BufferedReader reader = null;
		try {
			
			reader = new BufferedReader(new FileReader(file));
			while ((tempString = reader.readLine()) != null) {
				result += tempString + "
";
			}
			reader.close();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (reader != null) {
				try {
					reader.close();
				} catch (IOException e1) {
				}
			}
		}
		return result;
	}

     public static String url = null;
    public static String username = null;
    public static String password = null;
    public static Connection conn;
    public static Statement stmt;
    public static ResultSet rs;
    public static String fileName;
    public static String tempString = null;

    public static String PATH = "/dbconfig.properties";
    private static Properties properties;
    static {
        try {
            InputStream is = DBlUtils.class.getResourceAsStream(PATH);
            properties = new Properties();
            properties.load(is);
            url = properties.getProperty("jdbc.url");
            username = properties.getProperty("jdbc.username");
            password = properties.getProperty("jdbc.password");
            fileName = properties.getProperty("fileName");
            System.out.println("fileName:" + fileName);
            if (is != null)
                is.close();
        } catch (IOException e) {

            e.printStackTrace();
        }

    }

 查询mysql 数据库数据

   
/**
	 * 查询mysql 数据库数据，并获得内容
	 * 
	 * @param sql
	 */
	public static String queryDatas(String sql) {
		String queryDatas = null;
		try {
			conn = DriverManager.getConnection(url, username, password);
			conn.setAutoCommit(false);
			stmt = conn.prepareStatement("load data local infile '' " + "into table loadtest fields terminated by ','");
			StringBuilder sb = new StringBuilder();
			InputStream is = new ByteArrayInputStream(sb.toString().getBytes());
			((com.mysql.jdbc.Statement) stmt).setLocalInfileInputStream(is);
			ResultSet rs = stmt.executeQuery(sql);
			ResultSetMetaData rsmd = rs.getMetaData();
			int columnCount = rsmd.getColumnCount();
			// 输出列名
			for (int i = 1; i <= columnCount; i++) {
				if (rsmd.getColumnName(i).startsWith("content")) {
					System.out.print(rsmd.getColumnName(i));
				}
			}
			System.out.println();
			// 输出mysql数据
			while (rs.next()) {
				queryDatas = rs.getString(2);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return queryDatas;
	}

 文本读取的数据和mysql查询的数据进行比较：