java如何实现数值型二维数组和txt文件间的读存

[justmewei]

现有一数值型二维数组 double[][] value = new double[][] {
{ 5, 9, 2 },
{ 3, -4, 5 },
{ 2, 5, 1 },
{ -8, 3, 3 }};
现欲将其存入本地文件d:\\1.txt中，存入后再将数据读入 double[][] value，如何实现？

[stu202060510]

我自己写了一个，你参考下：

public class Test1 {
	public static void main(String[] args) throws IOException {
		double[][] value = new double[][] { { 5, 9, 2 }, { 3, -4, 5 },
				{ 2, 5, 1 }, { -8, 3, 3,3 } };
		File f = new File("d:/1.txt");
		writeArray(value,f);
		
		ArrayList<ArrayList<Double>> readArray = readArray(f);
		System.out.println(readArray);
	}
	
	public static ArrayList<ArrayList<Double>> readArray(File f){
		ArrayList<ArrayList<Double>> arrList=new ArrayList<ArrayList<Double>>();
		try {
			FileReader fr = new FileReader(f);
			BufferedReader br = new BufferedReader(fr);
			String line="";
			while((line = br.readLine())!=null){
				String[] split = line.split(",");
				ArrayList<Double> list=new ArrayList<Double>();
				for(String str:split){
					list.add(Double.parseDouble(str));
				}
				arrList.add(list);
			}
			br.close();
			fr.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return arrList;
	}
	
	public static void writeArray(double[][] arr,File file){
		try {
			FileWriter fw = new FileWriter(file);
			BufferedWriter bw = new BufferedWriter(fw);
			for (double[] v : arr) {
				for (double d : v) {
					bw.write(String.valueOf(d)+",");
				}
				bw.newLine();
			}
			bw.close();
			fw.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}

如果你实在想返回二维数组的话，就自己写个转换的函数

[若鱼1919]

import java.io.*;
public class Test{
   private static double[][] value = new double[][] { 
                                    { 5, 9, 2 }, 
                                    { 3, -4, 5 }, 
                                    { 2, 5, 1 }, 
                                    { -8, 3, 3 }
                                   }; 
   public static void write(String filepath)throws Exception{
        OutputStream out=new FileOutputStream(filepath);
        ObjectOutputStream oout=new ObjectOutputStream(out);
        oout.writeObject(value); 
   } 
   public static double[][] read(String filepath)throws Exception{
        InputStream in=new FileInputStream(filepath);
        ObjectInputStream oin=new ObjectInputStream(in);
        return (double[][])(oin.readObject());
   }
   public static void print(double[][] arr){
      if(arr==null){
           System.out.println("数组为空!");
           return;
      }
      int row=arr.length;
      int col=arr[0].length;
      //System.out.println("row="+row+",col="+col);
      System.out.println("{");
      for(int i=0;i<row;i++){
          System.out.print("{");
          for(int j=0;j<col;j++){
             System.out.print(arr[i][j]+" ");
          }
          System.out.print("}");
          System.out.println(); 
      }
      System.out.println("}");
   }
   public static void main(String args[])throws Exception{
       String filepath="d:\\1.txt";
       write(filepath);
       double[][] readResult=read(filepath);
       print(readResult);

   } 
}

[stu202060510]

楼上的写得很不错，学习了.......

[liguang168]

既然有人回复了。我就顶一下OK了。

[justmewei]

引用 2 楼 goldenfish1919 的回复:

Java codeimport java.io.*;publicclass Test{privatestaticdouble[][] value=newdouble[][] {
{5,9,2 },
{3,-4,5 },
?-

程序确实写的不错，学习学习，谢谢了。 不过为什么在将数组内容写入d:\\1.txt中后，显示的是乱码： ur [[D黔dgE xp ur [D>玞Z xp @ @" @ uq ~ @ @ @ uq ~ @ @ ?? uq ~ @ @ @