无法从数组列表中获取字符串值：仅获取[Ljava.lang.string @

Question

我正在将Outlook SCV文件解析为ArrayList。 然后，我希望获得String列表的Array值。

以下是代码：

 if(arr != null){
        try{
            for (int i = 1; i < arr.size(); i++) {
           oneRow = new ArrayList();
            oneRow.add(arr.get(i));
                for (int j = 0; j < oneRow.size(); j++) {

                StringBuilder strBuild = new StringBuilder();
                    strBuild.append(String.valueOf(oneRow.get(j).toString()));

以下是ArrayList：

无论我尝试了什么，我都无法获得String价值。 我得到的是：[Ljava.lang.string @ ....

以下是使ArrayList获取CSV文件并构建ArrayList的{​​{1}}的类：

public class ReadingCSV {


InputStream inputStream;

public ReadingCSV(InputStream inputStream){
    this.inputStream = inputStream;
}

public List read(){
    ArrayList resultList = new ArrayList();
    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
    try {
        String csvLine;
        while ((csvLine = reader.readLine()) != null) {
            String[] row = csvLine.split(",");
            resultList.add(row);
        }
    }
    catch (IOException ex) {
        throw new RuntimeException("Error in reading CSV file: "+ex);
    }
    finally {
        try {
            inputStream.close();
        }
        catch (IOException e) {
            throw new RuntimeException("Error while closing input stream: "+e);
        }
    }
    return resultList;
}
}

Answer 1

  

注意： - 使用jdk V1.8

编译和运行此代码

试试这个是一个有效的代码。你可以根据自己的需要进行操作。

public List<String> read(){
    ArrayList<String> resultList = new ArrayList(); //A Type-Safety (String) ArrayList
    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
    try {
        String csvLine;
        while ((csvLine = reader.readLine()) != null) {
            String[] row = csvLine.split(","); //row is String Array Object
            for(String eachWord : row) //Iterate each String from the array
            resultList.add(eachWord);  // add String to the Type-Safe ArrayList.
        }
    }catch (IOException ex) {
    throw new RuntimeException("Error in reading CSV file: "+ex);
}
finally {
    try {
        inputStream.close();
    }
    catch (IOException e) {
        throw new RuntimeException("Error while closing input stream: "+e);
    }
}
return resultList;
   }
  }

使用此

更新您的另一个代码

if(arr != null){
            for (int i = 1; i < arr.size(); i++) {
           ArrayList<String> oneRow = new ArrayList();
            oneRow.add(arr.get(i));
                for (int j = 0; j < oneRow.size(); j++) {
                    strBuild.append(oneRow.get(j));
                }
    }
    System.out.println(strBuild.toString());
}

  

本守则完美无缺。你可以自己尝试一下。如有任何问题，您可以发表评论。

Answer 2

为什么要双重转换为String：

strBuild.append（将String.valueOf（oneRow.get（J）的ToString（）））;

我认为，这有助于您： Help link