java - 漂亮的输出总是插入 "\r\n"

Question

我正在开发一个费用计算器。之前，我有一个有效的 XML 输出，但没有打印换行符。我认为有些事情搞砸了，也许编辑器没有将换行符视为换行符，不知道。

但是当我节省开支时，我得到了一个非常丑陋的输出:

"[ {\r\n\"标题\":\"2\",\r\n\"类别\":\"[无]\",\r\n\"句号\":\"年份\",\r\n\"值\":\"2\"\r\n}, {\r\n\"标题\":\"3\",\r\n\“类别\”:\“[无]\”，\r\n\“期间\”:\“年份\”，\r\n\“值\”:\“3\”\r\n } ]"

如果我查看控制台(在那里进行打印)，我会得到我想要的:

[ {
“标题”:“2”，
"类别": "[无]",
“期间”:“年份”，
“值”:“2”
}, {
“标题”:“3”，
"类别": "[无]",
“期间”:“年份”，
“值”:“3”
}]

目前，我的代码非常简单:

ObservableList<Expense> expenseList  = FXCollections.observableArrayList();
//The list gets edited by a TableView.
final ObjectMapper mapper = new ObjectMapper();
final String s = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(expenseList);
FileOutputStream fos = new FileOutputStream(path);
OutputStreamWriter outputFile = new OutputStreamWriter(fos, Charset.forName("UTF8"));

mapper.writeValue(outputFile, s);

这就是实体类的样子:

public class Expense {
    private StringProperty title = new SimpleStringProperty();
    private StringProperty category = new SimpleStringProperty();
    private StringProperty period = new SimpleStringProperty();
    private StringProperty value = new SimpleStringProperty();

    public void setTitle(String title) {
        this.title.set(title);
    }

    public void setCategory(String category) {
        this.category.set(category);
    }

    public void setPeriod(String period) {
        this.period.set(period);
    }

    public void setValue(String value) {
        this.value.set(value);
    }

    public Expense() {} //Default constructor is needed for XML-handling

    public Expense(String title, String value, String period, String category) {
        this.title = new SimpleStringProperty(title);
        this.value = new SimpleStringProperty(value);
        this.period = new SimpleStringProperty(period);
        this.category = new SimpleStringProperty(category);
    }

    public String getTitle() {
        return this.title.get();
    }

    public String getCategory() {
        return this.category.get();
    }

    public String getPeriod() {
        return this.period.get();
    }

    public String getValue() {
        return this.value.get();
    }

    public StringProperty titleProperty() {
        return this.title;
    }

    public StringProperty categoryProperty() {
        return this.category;
    }

    public StringProperty periodProperty() {
        return this.period;
    }

    public StringProperty valueProperty() {
        return this.value;
    }
}

我尝试获取列表中的每个字符串并将其转换为 json 字符串 -> 将其连接到我打印出来的一个大字符串。但结果相同。

Answer 1

这行代码的作用

mapper.writeValue(outputFile, s);

获取一个字符串并将其作为值写入 JSON 消息中。如果该字符串已经包含特殊字符，则必须将它们转义。

您最想要的可能是

 try (FileOutputStream fos = new FileOutputStream(path);
      OutputStreamWriter outputFile = new OutputStreamWriter(fos, StandardCharsets.UTF_8)) {
    outputFile .write(s); // just write the String as it is
}