Question

我想从用户输入搜索arraylist但我的if条件似乎不起作用。使用boolean和.contains（）对我的程序也不起作用。这是编码：

String phone;
phone=this.text1.getText();
System.out.println("this is the phone: " + phone);

BufferedReader line = new BufferedReader(new FileReader(new File("C:\\Users\\Laura Sutardja\\Documents\\IB DP\\Computer Science HL\\cs\\data.txt")));
    String indata;

    ArrayList<String[]> dataArr = new ArrayList<String[]>(); 

    while ((indata = line.readLine()) != null) { 

        String[] club = new String[2]; 
        String[] value = indata.split(",", 2);  
        //for (int i = 0; i < 2; i++) { 

            int n = Math.min(value.length, club.length);
              for (int i = 0; i < n; i++) { 
               club[i] = value[i]; 
        }
          boolean aa = dataArr.contains(this.text1.getText());

          if(aa==true)
          text2.setText("The data is found.");
          else
          text2.setText("The data is not found.");

        dataArr.add(club);
    }


    for (int i = 0; i < dataArr.size(); i++) {
        for (int x = 0; x < dataArr.get(i).length; x++) {
            System.out.printf("dataArr[%d][%d]: ", i, x);
            System.out.println(dataArr.get(i)[x]);
        }
    }


 }
 catch ( IOException iox )
{
  System.out.println("Error");
}

Answer 1

您的dataArr是String[]的列表，您正在搜索String。这两种是不同类型的物体。

我真的不知道club数组的内容是什么样的，但是您应该更改dataArr以保持普通String，或者编写一个方法在dataArr中迭代地查找包含String[]输出的this.text1.getText()。

Answer 2

该计划存在很多问题。我假设您要读取文本文件并将每行存储在arraylist中。为此，您必须拆分文本文件的每一行并将该数组存储在arrayList中。

String[] value;
while ((indata = line.readLine()) != null) { 
    value = indata.split(",");
    dataArr.add(value);
}

现在您拥有arrayList中文件的内容。接下来，您要将userinput与arraylist的每个元素进行比较。

int j = 0;
for (int i = 0; i < dataArr.size(); i++) {
    String[] phoneData = dataArr.get(i);
    if (phoneData[1].equals(phone)) { // i am assuming here that the phone number is the 2nd element of the String[] array, since i dont know how the textfile looks.
        System.out.println("Found number.");
        club[j++] = phoneData[1];
    } else if (i == dataArr.size()-1) {
        System.out.println("Didn't find number.");
    }
}

编辑：根据要求：

    String phone;
    phone = "38495";
    System.out.println("this is the phone: " + phone);

    BufferedReader line = new BufferedReader(new FileReader(new File("list.txt")));
    String indata;

    ArrayList<String[]> dataArr = new ArrayList<>();
    String[] club = new String[2];
    String[] value;// = indata.split(",", 2);
    while ((indata = line.readLine()) != null) {
        value = indata.split(",");
        dataArr.add(value);
    }
    int j = 0;
    for (int i = 0; i < dataArr.size(); i++) {
        String[] phoneData = dataArr.get(i);
        if (phoneData[1].equals(phone)) {
            System.out.println("Found number.");
            club[j++] = phoneData[1];
            break;
        } else if (i == dataArr.size()-1) {
            System.out.println("Didn't find number.");
        }
    }

我希望现在有道理。

从用户输入</string []>中搜索arraylist <string []>

2 个答案: