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流对第一项和最后一项做不同的事情,Java8

java-stream java

-2

QA_Col · 技术社区 · 7 年前

private static final String FS = System.getProperty("file.separator");
JFileChooser folderChooser = new JFileChooser();
if (folderChooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
      String filename = folderChooser.getSelectedFile().getPath();
      String[] recursivePaths = filename.split(FS);
      TreePath treePath = null;
      for (String part : recursivePaths) {
        int row = (treePath == null ? 0 : treePaths.getRowForPath(treePath));
        treePath = treePaths.getNextMatch(part, row, Position.Bias.Forward);
        if (treePath == null) {

        }
      }
}

但我想知道,是否可以使用Java8流,作为一种传统方式

private static final String FS = System.getProperty("file.separator");
JFileChooser folderChooser = new JFileChooser();
if (folderChooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
      String filename = folderChooser.getSelectedFile().getPath();
      String[] recursivePaths = filename.split(FS);
      Stream.of(recursivePaths).forEach(partFile -> {
          // Do something with FIRST, But How Discover?
          // Do something with OTHERS
          // Do something with LAST, But How Discover?
      });
}

2 回复 | 直到 7 年前

Joakim Danielson 7 年前

可能最好先处理后处理

private static final String FS = System.getProperty("file.separator");
JFileChooser folderChooser = new JFileChooser();
if (folderChooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
    String filename = folderChooser.getSelectedFile().getPath();
    String[] recursivePaths = filename.split(FS);
    String first = recursivePaths[0];
    String last = recursivePaths[recursivePaths.length - 1];

    Arrays.stream(recursivePaths, 1, recursivePaths.length - 1).forEach( x -> {
       //stream the elements in the middle
    });
  });
}

可能值得添加一些长度检查 recursivePaths