List lines=new ArrayList();
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 fileinput() {
// TODO Auto-generated method stub
List list = new ArrayList();
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 valueList = new ArrayList();//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 list = new ArrayList();
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
}
}
}
}
}
转播
