如何创建字符串格式模板来为Eclipse自动生成的toString生成Json

Question

Eclipse提供了为每个类自动生成toString方法的选项。

进一步利用这个功能，我正在创建字符串格式模板，在eclipse生成toString方法时作为Json格式提供。

我使用了以下字符串格式模板：

 { ${member.name()}:"${member.value}", ${otherMembers}}

现在我按照POJO生成toString方法，但是当我运行这个程序时，我得到的结果是而不是有效的JSON。

{ name:"null", reportees:"[1, 2, 3]", department:"[retail, banking, finance]", owns:"null", supplimentary:"null}

密码

public class TestPojo {
  private String name;
  private List<String> reportees;
  private String[] department;
  private Machine owns;
  private List<Machine> supplimentary;

public static void main(String arg[]) {
    TestPojo aTestPojo = new TestPojo();
    aTestPojo.department = new String[] { "retail", "banking", "finance" };
    aTestPojo.reportees = new ArrayList<String>() {

        {
            add("1");
            add("2");
            add("3");
        }
    };
    System.out.print(aTestPojo);
}

public static class Machine {

    private String machineName;
    private String duties;

    public String getMachineName() {
        return machineName;
    }

    public void setMachineName(String machineName) {
        this.machineName = machineName;
    }

    public String getDuties() {
        return duties;
    }

    public void setDuties(String duties) {
        this.duties = duties;
    }

    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("{ machineName:\"").append(machineName).append("\", duties:\"").append(duties).append("}");
        return builder.toString();
    }

}

@Override
public String toString() {
    StringBuilder builder = new StringBuilder();
    builder.append("{ name:\"").append(name).append("\", reportees:\"").append(reportees).append("\", department:\"").append(Arrays.toString(department)).append("\", owns:\"").append(owns).append("\", supplimentary:\"").append(supplimentary).append("}");
    return builder.toString();
}

}

Answer 1

仅推荐用于字符串值。下面的表达式为您提供了JSON toString生成。

{"${member.name()}":"${member.value}", "${otherMembers}"}

Answer 2

它不是有效的JSON，因为数组和集合的打印方式（“[1,2,3]”而不是[1,2,3]）。

此外，它不会通过严格的JSON验证，因为字段名也应该被引用。

Eclipse的字符串格式模板可能非常有用，但为了实现完全控制，最好创建一个生成器类。

这里有一个这样做的要点。您可以对其进行扩展，它适用于您的示例类。

您可以使用此类在Eclipse中生成toString（）方法。

Answer 3

借助@dvlcube idea。我构建了一个“Eclipse Custom toString（）builder”来生成toString方法代码，以返回当前对象的JSON格式字符串。

按照此解决方案的github单击[EclipsetoString_BuilderJSON]（https://github.com/djaganathan/EclipseToStringBuilderForJson/blob/master/src/main/java/com/github/djaganathan/opensource/eclipse/util/JsonToStringBuilder.java，自定义Eclipse toString（）Builder）

样本测试代码

import com.google.common.collect.Maps;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.commons.lang3.time.StopWatch;
import org.elasticsearch.common.collect.Lists;

public class TestPojo {

    private String name;
    private List<String> reportees;
    private String[] department;
    private Machine owns;
    private List<Machine> supplimentary;
    private int i = 10;
    private Map<String, Machine> machineList = Maps.newConcurrentMap();

    public static void main(String arg[]) {
        TestPojo aTestPojo = new TestPojo();
        aTestPojo.department = new String[] { "retail", "banking", "finance"};
        aTestPojo.reportees = new ArrayList<String>() {
            {
                add("1");
                add("2");
                add("3");
            }
        };

        Machine aMachine = new Machine("Train", "travel");
        Machine aMachine1 = new Machine("Lorry", "Carrier");
        aTestPojo.supplimentary = Lists.newArrayList(aMachine, aMachine1);
        aTestPojo.machineList.put("Train", aMachine);
        aTestPojo.machineList.put("Lorry", aMachine1);

        System.out.print(aTestPojo);
    }

    public static class Machine {
          private String machineName;
          private String duties;

        public Machine(String machineName, String duties) {
            super();
            this.machineName = machineName;
            this.duties = duties;
        }
        public String getMachineName() {
          return machineName;
        }
        public void setMachineName(String machineName) {
          this.machineName = machineName;
        }

      public String getDuties() {
          return duties;
      }

      public void setDuties(String duties) {
          this.duties = duties;
      }

    @Override
    public String toString() {
        JsonToStringBuilder builder = new JsonToStringBuilder(this);
        builder.append("machineName", machineName);
        builder.append("duties", duties);
        return builder.build();
    }
}

@Override
public String toString() {
    JsonToStringBuilder builder = new JsonToStringBuilder(this);
    builder.append("name", name);
    builder.append("reportees", reportees);
    builder.append("department", department);
    builder.append("owns", owns);
    builder.append("supplimentary", supplimentary);
    builder.append("i", i);
    builder.append("machineList", machineList);
    String value = builder.build();
    return value;
    }
}

运行此程序时，我得到了以下JSON输出

{"name": null,"reportees": ["1","2","3"],"department": ["retail","banking","finance"],"owns": null,"supplimentary": [{"machineName": "Train","duties": "travel"},{"machineName": "Lorry","duties": "Carrier"}],"i": 10,"machineList": {"Lorry": {"machineName": "Lorry","duties": "Carrier"},"Train": {"machineName": "Train","duties": "travel"}}}