我知道如何使用Java
和文件IOException来读取Scanner
的文件,但我唯一不知道的是如何将文本作为数组存储在文件中。
以下是我的代码snippet
:
public static void main(String[] args) throws IOException{
// TODO code application logic here
// // read KeyWestTemp.txt
// create token1
String token1 = "";
// for-each loop for calculating heat index of May - October
// create Scanner inFile1
Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt"));
// while loop
while(inFile1.hasNext()){
// how can I create array from text read?
// find next line
token1 = inFile1.nextLine();
以下是我的KeyWestTemp.txt
文件包含的内容:
70.3, 70.8, 73.8, 77.0, 80.7, 83.4, 84.5, 84.4, 83.4, 80.2, 76.3, 72.0
答案 0 :(得分:14)
存储为字符串:
public class ReadTemps {
public static void main(String[] args) throws IOException {
// TODO code application logic here
// // read KeyWestTemp.txt
// create token1
String token1 = "";
// for-each loop for calculating heat index of May - October
// create Scanner inFile1
Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt")).useDelimiter(",\\s*");
// Original answer used LinkedList, but probably preferable to use ArrayList in most cases
// List<String> temps = new LinkedList<String>();
List<String> temps = new ArrayList<String>();
// while loop
while (inFile1.hasNext()) {
// find next line
token1 = inFile1.next();
temps.add(token1);
}
inFile1.close();
String[] tempsArray = temps.toArray(new String[0]);
for (String s : tempsArray) {
System.out.println(s);
}
}
}
对于花车:
import java.io.File;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;
public class ReadTemps {
public static void main(String[] args) throws IOException {
// TODO code application logic here
// // read KeyWestTemp.txt
// create token1
// for-each loop for calculating heat index of May - October
// create Scanner inFile1
Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt")).useDelimiter(",\\s*");
// Original answer used LinkedList, but probably preferable to use ArrayList in most cases
// List<Float> temps = new LinkedList<Float>();
List<Float> temps = new ArrayList<Float>();
// while loop
while (inFile1.hasNext()) {
// find next line
float token1 = inFile1.nextFloat();
temps.add(token1);
}
inFile1.close();
Float[] tempsArray = temps.toArray(new Float[0]);
for (Float s : tempsArray) {
System.out.println(s);
}
}
}
答案 1 :(得分:2)
如果您不知道文件中的行数,则不会有用于初始化数组的大小。在这种情况下,使用List更有意义:
List<String> tokens = new ArrayList<String>();
while (inFile1.hasNext()) {
tokens.add(inFile1.nextLine());
}
之后,如果需要,可以复制到数组:
String[] tokenArray = tokens.toArray(new String[0]);
答案 2 :(得分:1)
while(inFile1.hasNext()){
token1 = inFile1.nextLine();
// put each value into an array with String#split();
String[] numStrings = line.split(", ");
// parse number string into doubles
double[] nums = new double[numString.length];
for (int i = 0; i < nums.length; i++){
nums[i] = Double.parseDouble(numStrings[i]);
}
}
答案 3 :(得分:0)
int count = -1;
String[] content = new String[200];
while(inFile1.hasNext()){
content[++count] = inFile1.nextLine();
}
修改强>
看起来你想创建一个float数组,为此创建一个float数组
int count = -1;
Float[] content = new Float[200];
while(inFile1.hasNext()){
content[++count] = Float.parseFloat(inFile1.nextLine());
}
那么你的浮点数就像
content[0] = 70.3
content[1] = 70.8
content[2] = 73.8
content[3] = 77.0 and so on
答案 4 :(得分:0)
只需将整个文件读入StringBuilder,然后按空格分割String。你将得到一个String数组。
Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt"));
StringBuilder sb = new Stringbuilder();
while(inFile1.hasNext()) {
sb.append(inFile1.nextLine());
}
String[] yourArray = sb.toString().split(", ");
答案 5 :(得分:0)
我发现这种从文件中读取字符串最适合我的方式
String st, full;
full="";
BufferedReader br = new BufferedReader(new FileReader(URL));
while ((st=br.readLine())!=null) {
full+=st;
}
“full”将是所有行的完整组合。如果要在文本行之间添加换行符,则可以执行此操作
full+=st+"\n";
答案 6 :(得分:-1)
我使用这种方法:
import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
public class TEST {
static Scanner scn;
public static void main(String[] args) {
String text = "";
try{
scn = new Scanner(new File("test.txt"));
}catch(FileNotFoundException ex){System.out.println(ex.getMessage());}
while(scn.hasNext()){
text += scn.next();
}
String[] arry = text.split(",");
//if need converting to float do this:
Float[] arrdy = new Float[arry.length];
for(int i = 0; i < arry.length; i++){
arrdy[i] = Float.parseFloat(arry[i]);
}
System.out.println(Arrays.toString(arrdy));
}
}