java - 将 jama 矩阵写入文件

Question

我想使用jama库将矩阵写入java文件。但是，只生成一个空文件。我正在使用下面的代码。可能出了什么问题？

PrintWriter writer = null;
    try {
        writer = new PrintWriter("deneme.txt", "UTF-8");
    } catch (FileNotFoundException | UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    m3.print( writer,2,2);

Answer 1

对于这行代码，

writer 可能为 null。将 m3.print(writer,2,2); 移动到 try block 内。

PrintWriter writer = null;
try {
    writer = new PrintWriter("deneme.txt", "UTF-8");
    m3.print(writer, 2, 2);
} catch (FileNotFoundException | UnsupportedEncodingException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}