1. java 查找TXT文件內容！！
找不到S開頭的字元???這句話是什麼意思？什麼叫S開頭的字元，一個字母就是一個字元。。
2. Java中通過txt文件存儲和取出數據
如果是這樣的話，你就先用string的split方法以,為分隔符號分開，再replace「」，這兩個東東就可以得到你要的中間的數據了。有個缺點比較佔用內存，或許你也可以去讀文件讀到,的時候就將之前的存起來，然後再讀下面的東西。思路而已試試看吧～
3. JAVA 如何輸出數據到TXT文件內
package test;
import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import javax.imageio.ImageIO;
public class ReadColorTest {
/**
* 讀取一張圖片的RGB值
*
* @throws Exception
*/
public void getImagePixel(String image) throws Exception {
File fileCar = new File("D:\\car.txt");
FileOutputStream fos = new FileOutputStream(fileCar);
BufferedOutputStream bos = new BufferedOutputStream(fos);
int[] rgb = new int[3];
File file = new File(image);
BufferedImage bi = null;
try {
bi = ImageIO.read(file);
} catch (Exception e) {
e.printStackTrace();
}
int width = bi.getWidth();
int height = bi.getHeight();
int minx = bi.getMinX();
int miny = bi.getMinY();
System.out.println("width=" + width + ",height=" + height + ".");
bos.write(("width=" + width + ",height=" + height + ".\n").getBytes());
System.out.println("minx=" + minx + ",miniy=" + miny + ".");
bos.write(("minx=" + minx + ",miniy=" + miny + ".\n").getBytes());
for (int i = minx; i < width; i++) {
for (int j = miny; j < height; j++) {
int pixel = bi.getRGB(i, j); // 下面三行代碼將一個數字轉換為RGB數字
rgb[0] = (pixel & 0xff0000) >> 16;
rgb[1] = (pixel & 0xff00) >> 8;
rgb[2] = (pixel & 0xff);
System.out.println("i=" + i + ",j=" + j + ":(" + rgb[0] + ","+ rgb[1] + "," + rgb[2] + ")");
bos.write(("i=" + i + ",j=" + j + ":(" + rgb[0] + ","+ rgb[1] + "," + rgb[2] + ")\n").getBytes());
}
}
}
/**
* 返回屏幕色彩值
*
* @param x
* @param y
* @return
* @throws AWTException
*/
public int getScreenPixel(int x, int y) throws AWTException { // 函數返回值為顏色的RGB值。
Robot rb = null; // java.awt.image包中的類，可以用來抓取屏幕，即截屏。
rb = new Robot();
Toolkit tk = Toolkit.getDefaultToolkit(); // 獲取預設工具包
Dimension di = tk.getScreenSize(); // 屏幕尺寸規格
System.out.println(di.width);
System.out.println(di.height);
Rectangle rec = new Rectangle(0, 0, di.width, di.height);
BufferedImage bi = rb.createScreenCapture(rec);
int pixelColor = bi.getRGB(x, y);
return 16777216 + pixelColor; // pixelColor的值為負，經過實踐得出：加上顏色最大值就是實際顏色值。
}
/**
* @param args
*/
public static void main(String[] args) throws Exception {
int x = 0;
ReadColorTest rc = new ReadColorTest();
x = rc.getScreenPixel(100, 345);
System.out.println(x + " - ");
rc.getImagePixel("D:\\car.jpg");
}
}
4. java如何寫入txt文件
用另一個構造方法
FileWriter fileWriter=new FileWriter("c:\\Result.txt", true); // true代表追加
同理
BufferedWriter writer = new BufferedWriter(new FileWriter(new File("c:\\Result.txt"), true));
5. Java中如何通過txt文件存儲和取出數據
Java中讀取txt文件可以使用file類先創建一個對象，然後使用I/O操作，進行讀取或者寫入操作，示例如下：
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
public class demo2 {
private static String path = "f:/demo1.txt";
private static File file;
static{
file = new File(path);
if(!file.exists()){
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) throws IOException {
Student stu = new Student(1,"張三",90);
writeDataToFile(file,stu);
readDataFromFile(file);
}
private static void readDataFromFile(File file) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String str = "";
while((str = reader.readLine())!=null){
String[] stuInfo = str.split(",");
System.out.println("學號："+stuInfo[0]+" 姓名："+stuInfo[1]+" score："+stuInfo[2]);
}
}
private static void writeDataToFile(File file,Student stu) throws FileNotFoundException {
PrintWriter out = new PrintWriter(new FileOutputStream(file, true));
out.println(stu.toString());
out.close();
}
}
6. java結果輸出至txt
幫你修改了一下 你看看可以嗎
package com.isoftstone.;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
public class Article {
//保存文章的內容
String content;
//保存分割後的單詞集合
String[] rawWords;
//保存統計後的單詞集合
String[] words;
//保存單詞對應的詞頻
int[] wordFreqs;
//構造函數，輸入文章內容
//提高部分：從文件中讀取
public Article() {
content =
"kolya is one of the richest films i've seen in some time . zdenek sverak plays a confirmed old bachelor ( who's likely to remain so ) , who finds his life as a czech cellist increasingly impacted by the five-year old boy that he's taking care of . though it ends rather abruptly-- and i'm whining , 'cause i wanted to spend more time with these characters-- the acting , writing , and proction values are as high as , if not higher than , comparable american dramas . this father-and-son delight-- sverak also wrote the script , while his son , jan , directed-- won a golden globe for best foreign language film and , a couple days after i saw it , walked away an oscar . in czech and russian , with english subtitles . ";
}
//對文章根據分隔符進行分詞,將結果保存到rawWords數組中
public void splitWord() {
//分詞的時候，因為標點符號不參與，所以所有的符號全部替換為空格
final char SPACE = ' '
content = content.replace(''', SPACE).replace(',', SPACE).replace('.', SPACE);
content = content.replace('(', SPACE).replace(')', SPACE).replace('-', SPACE);
rawWords = content.split("\s+");//凡是空格隔開的都算單詞，上面替換了', 所以I've 被分成2個 //單詞
}
//統計詞，遍歷數組
public void countWordFreq() {
//將所有出現的字元串放入唯一的set中，不用map,是因為map尋找效率太低了
Set<String> set = new TreeSet<String>();
for (String word : rawWords) {
set.add(word);
}
Iterator ite = set.iterator();
List<String> wordsList = new ArrayList<String>();
List<Integer> freqList = new ArrayList<Integer>();
//多少個字元串未知，所以用list來保存先
while (ite.hasNext()) {
String word = (String) ite.next();
int count = 0;//統計相同字元串的個數
for (String str : rawWords) {
if (str.equals(word)) {
count++;
}
}
wordsList.add(word);
freqList.add(count++);
}
//存入數組當中
words = wordsList.toArray(new String[0]);
wordFreqs = new int[freqList.size()];
for (int i = 0; i < freqList.size(); i++) {
wordFreqs[i] = freqList.get(i);
}
}
//根據詞頻，將詞數組和詞頻數組進行降序排序
public void sort() {
class Word {
private String word;
private int freq;
public Word(String word, int freq) {
this.word = word;
this.freq = freq;
}
}
//注意：此處排序，1）首先按照詞頻降序排列， 2）如果詞頻相同，按照字母降序排列，
//如 'abc' > 'ab' >'aa'
class WordComparator implements Comparator {
public int compare(Object o1, Object o2) {
Word word1 = (Word) o1;
Word word2 = (Word) o2;
if (word1.freq < word2.freq) {
return 1;
} else if (word1.freq > word2.freq) {
return -1;
} else {
int len1 = word1.word.trim().length();
int len2 = word2.word.trim().length();
String min = len1 > len2 ? word2.word : word1.word;
String max = len1 > len2 ? word1.word : word2.word;
for (int i = 0; i < min.length(); i++) {
if (min.charAt(i) < max.charAt(i)) {
return 1;
}
}
return 1;
}
}
}
List wordList = new ArrayList<Word>();
for (int i = 0; i < words.length; i++) {
wordList.add(new Word(words[i], wordFreqs[i]));
}
Collections.sort(wordList, new WordComparator());
for (int i = 0; i < wordList.size(); i++) {
Word wor = (Word) wordList.get(i);
words[i] = wor.word;
wordFreqs[i] = wor.freq;
}
}
//將排序結果輸出
public void printResult() {
System.out.println("Total " + words.length + " different words in the content!");
for (int i = 0; i < words.length; i++) {
System.out.println(wordFreqs[i] + " " + words[i]);
}
}
// 輸出到文本
private void outputResult() {
File file = new File("C:\output.txt");
try {
if (file.exists()) file.delete();
BufferedWriter bw = new BufferedWriter(new FileWriter(file));
StringBuffer out = new StringBuffer();
for(int i = 0; i < words.length; i++) {
out.append(wordFreqs[i] + " " + words[i] + " ");
}
bw.write(out.toString());
bw.flush();
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
//測試類的功能
public static void main(String[] args) {
Article a = new Article();
a.splitWord();
a.countWordFreq();
a.sort();
a.printResult();
a.outputResult();
}
}
7. java 寫txt文件
import java.io.*;
public class Test {
public static void main(String[] args){
String s = new String();
String s1 = new String();
try {
File f = new File("E:\\123.txt");
if(f.exists()){
System.out.print("文件存在");
}else{
System.out.print("文件不存在");
f.createNewFile();//不存在則創建
}
BufferedReader input = new BufferedReader(new FileReader(f));
while((s = input.readLine())!=null){
s1 += s+"\n";
}
System.out.println(s1);
input.close();
s1 += "添加的內容!";
BufferedWriter output = new BufferedWriter(new FileWriter(f));
output.write(s1);
output.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
8. Java txt操作問題
public static void main(String[] args) throws IOException {
BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream("d:/AA.txt")));
String str=br.readLine();
int num=str.indexOf("名稱：");
int n="名稱：".length();
StringBuffer sb=new StringBuffer(str);
StringBuffer s=sb.delete(0, num+n);
String name=s.toString();
br.close();
System.out.println(name);
}
9. 如何在Java中打開TXT文件
importjava.io.File;
importjava.io.FileInputStream;
importjava.io.FileNotFoundException;
importjava.io.IOException;
publicclassReadText{
publicstaticvoidmain(String[]args)
{
readTextContent();
}
()
{
try
{
Filefile=newFile("E://test.txt");
FileInputStreamfis=newFileInputStream(file);
Stringstr="";
byte[]bytes=newbyte[1024];
intlength=0;
while((length=fis.read(bytes))!=-1)
{
str+=newString(bytes,0,length);
}
System.out.println(str);
}catch(FileNotFoundExceptione)
{
e.printStackTrace();
}catch(IOExceptione)
{
e.printStackTrace();
}
}
}
10. 如何用JAVA生成TXT文件
生成TXT的方法有很多的。常用位位元組流和字元流
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
public class TextFileGenerator {
public static void main(String[] args) throws Exception {
method1();
method2();
}
private static void method1() throws Exception {
String txtContent = "Hello World!";
File file = new File("test1.txt");
FileWriter fw = new FileWriter(file);
fw.write(txtContent);
fw.close();
}
private static void method2() throws Exception {
String txtContent = "Hello World!";
File file = new File("test2.txt");
FileOutputStream fos = new FileOutputStream(file);
fos.write(txtContent.getBytes());
fos.close();
}
}