add methods

CHANGELOG.md

@@ -10,6 +10,7 @@
 * 【core   】     增加RingIndexUtil（pr#438@Gitee）
 * 【core   】     Assert增加checkBetween重载（pr#436@Gitee）
 * 【core   】     ReUtil增加命名分组重载（pr#439@Gitee）
+* 【json   】     toString和writer增加Filter（issue#I4DQNQ@Gitee）
 * 
 ### 🐞Bug修复
 * 【core   】     修复CollUtil.isEqualList两个null返回错误问题（issue#1885@Github）

hutool-json/src/main/java/cn/hutool/json/JSONArray.java

@@ -3,6 +3,8 @@ package cn.hutool.json;
 import cn.hutool.core.bean.BeanPath;
 import cn.hutool.core.collection.ArrayIter;
 import cn.hutool.core.collection.CollUtil;
+import cn.hutool.core.lang.Filter;
+import cn.hutool.core.lang.Pair;
 import cn.hutool.core.text.StrJoiner;
 import cn.hutool.core.util.ArrayUtil;
 import cn.hutool.core.util.ObjectUtil;
@@ -12,6 +14,7 @@ import cn.hutool.json.serialize.GlobalSerializeMapping;
 import cn.hutool.json.serialize.JSONSerializer;
 import cn.hutool.json.serialize.JSONWriter;
 
+import java.io.StringWriter;
 import java.io.Writer;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -529,11 +532,48 @@ public class JSONArray implements JSON, JSONGetter<Integer>, List<Object>, Rando
 		return this.toJSONString(0);
 	}
 
+	/**
+	 * 返回JSON字符串<br>
+	 * 支持过滤器，即选择哪些字段或值不写出
+	 *
+	 * @param indentFactor 每层缩进空格数
+	 * @param filter 键值对过滤器
+	 * @return JSON字符串
+	 * @since 5.7.15
+	 */
+	public String toJSONString(int indentFactor, Filter<Pair<Integer, Object>> filter){
+		final StringWriter sw = new StringWriter();
+		synchronized (sw.getBuffer()) {
+			return this.write(sw, indentFactor, 0, filter).toString();
+		}
+	}
+
 	@Override
 	public Writer write(Writer writer, int indentFactor, int indent) throws JSONException {
+		return write(writer, indentFactor, indent, null);
+	}
+
+	/**
+	 * 将JSON内容写入Writer<br>
+	 * 支持过滤器，即选择哪些字段或值不写出
+	 *
+	 * @param writer       writer
+	 * @param indentFactor 缩进因子，定义每一级别增加的缩进量
+	 * @param indent       本级别缩进量
+	 * @param filter       过滤器
+	 * @return Writer
+	 * @throws JSONException JSON相关异常
+	 * @since 5.7.15
+	 */
+	public Writer write(Writer writer, int indentFactor, int indent, Filter<Pair<Integer, Object>> filter) throws JSONException {
 		final JSONWriter jsonWriter = JSONWriter.of(writer, indentFactor, indent, config)
 				.beginArray();
-		this.forEach(jsonWriter::writeValue);
+
+		CollUtil.forEach(this, (value, index)->{
+			if (null == filter || filter.accept(new Pair<>(index, value))) {
+				jsonWriter.writeValue(value);
+			}
+		});
 		jsonWriter.end();
 		// 此处不关闭Writer，考虑writer后续还需要填内容
 		return writer;

hutool-json/src/main/java/cn/hutool/json/JSONObject.java

@@ -6,6 +6,8 @@ import cn.hutool.core.bean.copier.BeanCopier;
 import cn.hutool.core.bean.copier.CopyOptions;
 import cn.hutool.core.collection.CollectionUtil;
 import cn.hutool.core.convert.Convert;
+import cn.hutool.core.lang.Filter;
+import cn.hutool.core.lang.Pair;
 import cn.hutool.core.map.CaseInsensitiveLinkedMap;
 import cn.hutool.core.map.CaseInsensitiveMap;
 import cn.hutool.core.map.MapUtil;
@@ -18,6 +20,7 @@ import cn.hutool.json.serialize.JSONObjectSerializer;
 import cn.hutool.json.serialize.JSONSerializer;
 import cn.hutool.json.serialize.JSONWriter;
 
+import java.io.StringWriter;
 import java.io.Writer;
 import java.math.BigDecimal;
 import java.math.BigInteger;
@@ -552,17 +555,54 @@ public class JSONObject implements JSON, JSONGetter<String>, Map<String, Object>
 		return this.toJSONString(0);
 	}
 
+	/**
+	 * 返回JSON字符串<br>
+	 * 支持过滤器，即选择哪些字段或值不写出
+	 *
+	 * @param indentFactor 每层缩进空格数
+	 * @param filter 键值对过滤器
+	 * @return JSON字符串
+	 * @since 5.7.15
+	 */
+	public String toJSONString(int indentFactor, Filter<Pair<String, Object>> filter){
+		final StringWriter sw = new StringWriter();
+		synchronized (sw.getBuffer()) {
+			return this.write(sw, indentFactor, 0, filter).toString();
+		}
+	}
+
 	@Override
 	public Writer write(Writer writer, int indentFactor, int indent) throws JSONException {
+		return write(writer, indentFactor, indent, null);
+	}
+
+	/**
+	 * 将JSON内容写入Writer<br>
+	 * 支持过滤器，即选择哪些字段或值不写出
+	 *
+	 * @param writer       writer
+	 * @param indentFactor 缩进因子，定义每一级别增加的缩进量
+	 * @param indent       本级别缩进量
+	 * @param filter       过滤器
+	 * @return Writer
+	 * @throws JSONException JSON相关异常
+	 * @since 5.7.15
+	 */
+	public Writer write(Writer writer, int indentFactor, int indent, Filter<Pair<String, Object>> filter) throws JSONException {
 		final JSONWriter jsonWriter = JSONWriter.of(writer, indentFactor, indent, config)
 				.beginObj();
-		this.forEach(jsonWriter::writeField);
+		this.forEach((key, value) -> {
+			if (null == filter || filter.accept(new Pair<>(key, value))) {
+				jsonWriter.writeField(key, value);
+			}
+		});
 		jsonWriter.end();
-
+		// 此处不关闭Writer，考虑writer后续还需要填内容
 		return writer;
 	}
 
 	// ------------------------------------------------------------------------------------------------- Private method start
+
 	/**
 	 * Bean对象转Map
 	 *

hutool-json/src/test/java/cn/hutool/json/JSONArrayTest.java

@@ -239,4 +239,28 @@ public class JSONArrayTest {
 		private Integer id;
 		private String name;
 	}
+
+	@Test
+	public void filterIncludeTest(){
+		JSONArray json1 = JSONUtil.createArray()
+				.set("value1")
+				.set("value2")
+				.set("value3")
+				.set(true);
+
+		final String s = json1.toJSONString(0, (pair) -> pair.getValue().equals("value2"));
+		Assert.assertEquals("[\"value2\"]", s);
+	}
+
+	@Test
+	public void filterExcludeTest(){
+		JSONArray json1 = JSONUtil.createArray()
+				.set("value1")
+				.set("value2")
+				.set("value3")
+				.set(true);
+
+		final String s = json1.toJSONString(0, (pair) -> false == pair.getValue().equals("value2"));
+		Assert.assertEquals("[\"value1\",\"value3\",true]", s);
+	}
 }

hutool-json/src/test/java/cn/hutool/json/JSONObjectTest.java

@@ -609,4 +609,28 @@ public class JSONObjectTest {
 	class BigDecimalBean{
 		private BigDecimal orderId;
 	}
+
+	@Test
+	public void filterIncludeTest(){
+		JSONObject json1 = JSONUtil.createObj(JSONConfig.create().setOrder(true))
+				.set("a", "value1")
+				.set("b", "value2")
+				.set("c", "value3")
+				.set("d", true);
+
+		final String s = json1.toJSONString(0, (pair) -> pair.getKey().equals("b"));
+		Assert.assertEquals("{\"b\":\"value2\"}", s);
+	}
+
+	@Test
+	public void filterExcludeTest(){
+		JSONObject json1 = JSONUtil.createObj(JSONConfig.create().setOrder(true))
+				.set("a", "value1")
+				.set("b", "value2")
+				.set("c", "value3")
+				.set("d", true);
+
+		final String s = json1.toJSONString(0, (pair) -> false == pair.getKey().equals("b"));
+		Assert.assertEquals("{\"a\":\"value1\",\"c\":\"value3\",\"d\":true}", s);
+	}
 }