java需要从.txt文本里读取特定的字段，并写入另一个.txt
读取之前
读取之后
a,b,c,....e是表示标签，先的是数据，我需要读取特定标签下面的数据，麻烦写个代码，谢谢，我刚学java，超级菜鸟，别嘲笑，现在力求进步，谢谢大佬们，运行成功，就给币。
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class TestAAA {
public static void main(String[] args) throws Exception {
File file = new File("C:\\Users\\Administrator\\Desktop\\新建文本文档.txt");
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File("C:\\Users\\Administrator\\Desktop\\新建文本文档1.txt")),"UTF-8"));
String[] strs = {"a", "b", "d", "e"};//要读的标签
int num[] = new int[strs.length];//每个标签的位置
String[] left = new String[strs.length];
String[] right = new String[strs.length];
BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(file));
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream),5*1024*1024);
String line = null;
if((line = reader.readLine()) != null) {
String[] infoArraay = line.split(" ");
for (int i = 0; i < strs.length; i++) {
for (int j = 0; j < infoArraay.length; j++) {
int begin = 0;
if((begin=infoArraay[j].indexOf(strs[i]))!=-1) {
num[i] = j;
String leftStr = infoArraay[j].substring(0, begin);;
String rightStr = infoArraay[j].substring(begin+strs[i].length()-1, infoArraay[j].length()-1);
left[i] = leftStr;
right[i] = rightStr;
writer.write(infoArraay[j]+" ");
break;
}
}
}
writer.newLine();
}
while((line = reader.readLine()) != null) {//逐行的读
String[] infoArraay = line.split(" ");
String str = "";
for (int i = 0; i < num.length; i++) {
str += infoArraay[num[i]].replace(left[i], "").replace(right[i], "")+",";
}
str = str.substring(0, str.length()-1);
writer.write(str);
writer.newLine();
}
reader.close();
writer.close();
}
}
改了下，你试试
运行前
a b c d .....e.....
a1 b1 c1 d1 .....e1.....
a2 b2 c2 d2 .....e2.....
a3 b3 c3 d3 .....e3.....
a4 b4 c4 d4 .....e4.....
a5 b5 c5 d5 .....e5.....
a6 b6 c6 d6 .....e6.....
a7 b7 c7 d7 .....e7.....
a8 b8 c8 d8 .....e8.....
a9 b9 c9 d9 .....e9.....
运行后
a b d e
a1,b1,d1,e1
a2,b2,d2,e2
a3,b3,d3,e3
a4,b4,d4,e4
a5,b5,d5,e5
a6,b6,d6,e6
a7,b7,d7,e7
a8,b8,d8,e8
a9,b9,d9,e9
不是e8，是e7，也就是数据了。其实都无所谓
不会java，好气啊，不过从思路上来说，你就是逐行读取，然后按字符串拆分，之后找出需要的列，写入到新的文件内就可以。
import java.io.*;
import java.util.ArrayList;
import java.util.List;
public class ReadText {
public static List<TxtRow> readFileByLines(String fileName) {
//File file = new File(fileName);
List<TxtRow> list = new ArrayList<>();
BufferedReader reader = null;
try{
reader = new BufferedReader(new InputStreamReader(new FileInputStream(fileName),"UTF-8"));
String tempString = null;
int line = 1;
while ((tempString = reader.readLine()) != null) {
System.out.println("line " + line + ": " + tempString);
tempString.trim(); //清空首尾的空格
/*System.out.println("-------------只有一个间隔--------------------");
String [] strs = tempString.split(" "); //第一次分割是还没有替换空格的，和下边做对比
for(int i=0;i<strs.length;i++) {
System.out.println(strs[i]);
}*/
System.out.println("-------------间隔不固定--------------------");
String string = tempString.replaceAll(" {1,}", " "); //替换多个空格
String [] strs2 = string.split(" "); //以空格作为分割，打印输出,注意txt中不要出现tab打出来的缩进空格
TxtRow txtRow = new TxtRow();
for(int i=0;i<strs2.length;i++) {
System.out.println(strs2[i]);
if(i==0){
txtRow.setFirst(strs2[i]);
}else if(i==1){
txtRow.setSecond(strs2[i]);
}
}
list.add(txtRow);
line++;
}
reader.close();
}catch (IOException e){
e.printStackTrace();
}finally {
if (reader != null){
try{
reader.close();
}catch (IOException e1){
}
}
}
return list;
}
public static void writeToTxt(List<TxtRow> list){
StringBuilder sb = new StringBuilder();
for(int i=0;i<list.size();i++){
sb.append(list.get(i).getFirst()+" "+list.get(i).getSecond()).append("\r\n");
}
// write string to file
try{
FileWriter writer = new FileWriter("D:\\workspace\\test2.txt");
BufferedWriter bw = new BufferedWriter(writer);
bw.write(sb.toString());
bw.close();
writer.close();
}catch(Exception e){
e.printStackTrace();
}
}
public static void main(String args[]){
String filename = "D:\\workspace\\test.txt";
List<TxtRow> li = readFileByLines(filename);
System.out.println(li);
writeToTxt(li);
}
}
public class TxtRow {
private String first;
private String second;
public TxtRow() {
}
public TxtRow(String first, String second) {
this.first = first;
this.second = second;
}
public String getFirst() {
return first;
}
public void setFirst(String first) {
this.first = first;
}
public String getSecond() {
return second;
}
public void setSecond(String second) {
this.second = second;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder("{");
sb.append("\"first\":\"")
.append(first).append('\"');
sb.append(",\"second\":\"")
.append(second).append('\"');
sb.append('}');
return sb.toString();
}
}
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class TestAAA {
public static void main(String[] args) throws Exception {
File file = new File("C:\\Users\\Administrator\\Desktop\\新建文本文档.txt");
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File("C:\\Users\\Administrator\\Desktop\\新建文本文档1.txt")),"UTF-8"));
String[] strs = {"a", "b", "d", "e"};//要读的标签
int num[] = new int[strs.length];//每个标签的位置
BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(file));
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream),5*1024*1024);
String line = null;
if((line = reader.readLine()) != null) {
String[] infoArraay = line.split("\t");
for (int i = 0; i < strs.length; i++) {
for (int j = 0; j < infoArraay.length; j++) {
if(infoArraay[j].equals(strs[i])) {
num[i] = j;
writer.write(infoArraay[j]+"\t");
break;
}
}
}
writer.newLine();
}
while((line = reader.readLine()) != null) {//逐行的读
String[] infoArraay = line.split("\t");
String str = "";
for (int i = 0; i < num.length; i++) {
str += infoArraay[num[i]]+",";
}
str = str.substring(0, str.length()-1);
writer.write(str);
writer.newLine();
}
reader.close();
writer.close();
}
}
我这全部都是制表符，txt没有空格的
如果你的txt文件的空白地方是空格要把\t换成空格
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class TestAAA {
public static void main(String[] args) throws Exception {
File file = new File("C:\\Users\\Administrator\\Desktop\\新建文本文档.txt");
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File("C:\\Users\\Administrator\\Desktop\\新建文本文档1.txt")),"UTF-8"));
String[] strs = {"a", "b", "d", "e"};//要读的标签
int num[] = new int[strs.length];//每个标签的位置
BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(file));
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream),5*1024*1024);
String line = null;
if((line = reader.readLine()) != null) {
String[] infoArraay = line.split(" ");
for (int i = 0; i < strs.length; i++) {
for (int j = 0; j < infoArraay.length; j++) {
if(infoArraay[j].equals(strs[i])) {
num[i] = j;
writer.write(infoArraay[j]+" ");
break;
}
}
}
writer.newLine();
}
while((line = reader.readLine()) != null) {//逐行的读
String[] infoArraay = line.split(" ");
String str = "";
for (int i = 0; i < num.length; i++) {
str += infoArraay[num[i]]+",";
}
str = str.substring(0, str.length()-1);
writer.write(str);
writer.newLine();
}
reader.close();
writer.close();
}
}
空格的
你的文件是不是有多个空格啊？
试试这个：
public class Test {
public static void main(String[] args){
File fileR = new File("C:/Users/CXDOG/Desktop/testR.txt");
File fileW = new File("C:/Users/CXDOG/Desktop/testW.txt");
try {
BufferedReader br = new BufferedReader(new FileReader(fileR));
BufferedWriter bw = new BufferedWriter(new FileWriter(fileW ));
String s;
String[] ss;
Pattern p = Pattern.compile("(\\s)+");
while( (s = br.readLine() ) != null){
System.out.println(s);
Matcher m = p.matcher(s);
if (m.find() ){
s = s.replaceAll(m.group(1), ",");
bw.write(s);
bw.newLine();
bw.flush();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
你自己看着封装优化