java读取文件乱码

List<String> lines=new ArrayList<String>();
BufferedReader br = new BufferedReader(new FileReader(fileName));
String line = null;
while ((line = br.readLine()) != null) {
      lines.add(line);
}
br.close();

　　

Java的I/O类处理如图：

Reader 类是 Java 的 I/O 中读字符的父类，而 InputStream 类是读字节的父类，InputStreamReader 类就是关联字节到字符的桥梁，它负责在 I/O 过程中处理读取字节到字符的转换，而具体字节到字符的解码实现它由 StreamDecoder 去实现，在 StreamDecoder 解码过程中必须由用户指定 Charset 编码格式。值得注意的是如果你没有指定 Charset，将使用本地环境中的默认字符集，例如在中文环境中将使用 GBK 编码。

总结：Java读取数据流的时候，一定要指定数据流的编码方式，否则将使用本地环境中的默认字符集。

public static List<Organ> fileinput() {
		// TODO Auto-generated method stub
		List<Organ> list = new ArrayList<Organ>();
		try {
			String fileName = "C://Users/Administrator/Desktop/备份/bustno.txt";
			StringBuffer sb = new StringBuffer("");
			InputStreamReader sr = new InputStreamReader(new FileInputStream(fileName),"UTF-8");
			BufferedReader br = new BufferedReader(sr);

			String str = null;
			while ((str = br.readLine()) != null) {
				String[] firstSplit = str.split("\n");
				int recordNum = firstSplit.length;
				for(int i=0; i < recordNum;i++){
					String[] one = str.split("\\|");
						Organ organ = new Organ();
						organ.setParentID(0);
						organ.setOrganValue(one[0].substring(0, 3));
						organ.setOrganName(one[1]);
						list.add(organ);
				}
			}

			br.close();
			sr.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.print("read succeeded");
		return list;

	}

　list结果集分组：

	private static void fenzu(String filepath) throws IOException, ParseException {
		// TODO Auto-generated method stub
		SimpleDateFormat simpleDate = new SimpleDateFormat("yyyy-MM");
		List<String[][]> valueList = new ArrayList<String[][]>();//将结果集转化为二维数组
		  StringBuffer sb = new StringBuffer("");
          InputStreamReader sr = new InputStreamReader(new FileInputStream(filepath),"UTF-8");
          BufferedReader br = new BufferedReader(sr);
          String str = null;
          List<Canal> list = new ArrayList<Canal>();
          while ((str = br.readLine()) != null) {
              String[] firstSplit = str.split("\n");
              int recordNum = firstSplit.length;
              for(int i=0; i < recordNum;i++){
                  String[] one = str.split("\t");
                  Canal canalone = new Canal();
                  canalone.setCanal(one[0]);
                  canalone.setSa_tx_m(one[1]);
                  canalone.setCr_tx_amt(one[2]);
                  list.add(canalone);
              }}

          System.out.print("list size :"+list.size()+ "\n");
      	//结果集分组
    		List uniqueList = new ArrayList();//存放Canal个数
    		for (int j = 0; j < list.size(); j++) {
    			Canal canal = list.get(j);
    			if (!uniqueList.contains(canal.getCanal()))
    			{
    				System.out.print("uniqueList not contains : " +canal.getCanal().toString() + "\n" );
    				String[][] b = new String[2][12];//String[0][]为canal,长度为1，String[1][]对应每个月的数值
    				b[0][0] = canal.getCanal();//canal
    				String amtValue = list.get(j).getCr_tx_amt();// 金额
    				Calendar Date = Calendar.getInstance();
    				Date.setTime(simpleDate.parse(canal.getSa_tx_m()));
    				int month = Date.get(Calendar.MONTH); // 因为数组的编号要减一，这里不用加一
    				b[1][month] = amtValue;
    				uniqueList.add(canal.getCanal());//将canal种类放在集合里
    				valueList.add(b);//将数值集合放在valueList里
    			} else {
    				for (int k = 0; k < valueList.size(); k++) {
    					String[][] b = valueList.get(k);
    					if (b[0][0].equals(canal.getCanal())) {
    						valueList.remove(k);//先remove结果集里不完整的记录
    						System.out.print("has found canal : " + canal.getCanal() + "\n");
    						String amtValue = canal.getCr_tx_amt();// 金额
    						Calendar Date = Calendar.getInstance();
    						Date.setTime(simpleDate.parse(canal
    								.getSa_tx_m()));
    						int month = Date.get(Calendar.MONTH); // 因为数组的编号要减一，这里不用加一
    						b[1][month] = amtValue.toString();
    						valueList.add(b);//加了数值再add到分组的list里
    						break; //找到就返回
    					}
    				}
    			}
    		}

	}