问题形容

public class Demo {
    private Boolean isHot;
    private Boolean isQuick;

    public Boolean getHot() {return isHot;}

    public void setHot(Boolean hot) {isHot = hot;}

    public Boolean getQuick() {return isQuick;}

    public void setQuick(Boolean quick) {isQuick = quick;}
}

例如下面一个 bean，getset 办法均为 idea 主动生成的（Idea 2020.1），Fastjson 序列化后的后果为

{
    "hot":true,
    "quick":true
}

咱们其实冀望的是

{
    "isHot":true,
    "isQuick":true
}

解决方案

计划一

批改 get 办法为getIsXXX
public Boolean getHot() ->public Boolean getIsHot()

计划二

去掉 getset 办法应用 lombok，如果公司容许的话

计划三

批改 idea 默认模板

#set($paramName = $helper.getParamName($field, $project))
#if($field.modifierStatic)
static ##
#end
$field.type ##
#set($name = $StringUtil.capitalizeWithJavaBeanConvention($StringUtil.sanitizeJavaIdentifier($helper.getPropertyName($field, $project))))
#if ($field.name == $paramName)
get##
#else
getIs##
#end
${name}() {
return this.##
$field.name;
}

计划四

不要以 is 结尾，退出公司的代码标准，《Java 开发手册（泰山版）》中也提到了

【强制】POJO 类中的任何布尔类型的变量，都不要加 is 前缀，否则局部框架解析会引起序列 化谬误。

源码剖析

上面咱们看一下 Fastjson 源码

public static List<FieldInfo> computeGetters(Class<?> clazz, //
                                             JSONType jsonType, //
                                             Map<String,String> aliasMap, //
                                             Map<String,Field> fieldCacheMap, //
                                             boolean sorted, //
                                             PropertyNamingStrategy propertyNamingStrategy //
){Map<String,FieldInfo> fieldInfoMap = new LinkedHashMap<String,FieldInfo>();
    boolean kotlin = TypeUtils.isKotlin(clazz);
    // for kotlin
    Constructor[] constructors = null;
    Annotation[][] paramAnnotationArrays = null;
    String[] paramNames = null;
    short[] paramNameMapping = null;
    Method[] methods = clazz.getMethods();
    for(Method method : methods){
       ..... 此处省略
        
        // 次要是这里
        if(methodName.startsWith("get")){if(methodName.length() < 4){continue;}
            if(methodName.equals("getClass")){continue;}
            if(methodName.equals("getDeclaringClass") && clazz.isEnum()){continue;}
            char c3 = methodName.charAt(3);
            String propertyName;
            Field field = null;
            if(Character.isUpperCase(c3) //
                    || c3 > 512 // for unicode method name
                    ){if(compatibleWithJavaBean){
                    // 依据 get 办法取值
                    propertyName = decapitalize(methodName.substring(3));
                } else{propertyName = Character.toLowerCase(methodName.charAt(3)) + methodName.substring(4);
                }
                propertyName = getPropertyNameByCompatibleFieldName(fieldCacheMap, methodName, propertyName, 3);
            } 
            
         ...... 再度省略
            fieldInfoMap.put(propertyName, fieldInfo);
        }
    }
    Field[] fields = clazz.getFields();
    computeFields(clazz, aliasMap, propertyNamingStrategy, fieldInfoMap, fields);
    return getFieldInfos(clazz, sorted, fieldInfoMap);
}

前面就基本上以这个名称为准了。

这个 writer 是通过动静生成的一个 bean，所以代码无奈追踪，然而它强转了下 `
return (JavaBeanSerializer) instance;
所以咱们能够看下 JavaBeanSerializer::write 办法看下是如何把 bean 转成String 的 `

    protected void write(JSONSerializer serializer, //
                      Object object, //
                      Object fieldName, //
                      Type fieldType, //
                      int features,
                      boolean unwrapped
    ) throws IOException {
        SerializeWriter out = serializer.out;

        if (object == null) {out.writeNull();
            return;
        }

        if (writeReference(serializer, object, features)) {return;}

        final FieldSerializer[] getters;
                // 获取咱们刚刚解析的成员变量 c h
        if (out.sortField) {getters = this.sortedGetters;} else {getters = this.getters;}

        SerialContext parent = serializer.context;
        if (!this.beanInfo.beanType.isEnum()) {serializer.setContext(parent, object, fieldName, this.beanInfo.features, features);
        }

        final boolean writeAsArray = isWriteAsArray(serializer, features);

        FieldSerializer errorFieldSerializer = null;
        try {
            final char startSeperator = writeAsArray ? '[' : '{';
            final char endSeperator = writeAsArray ? ']' : '}';
            if (!unwrapped) {
                // 全程增加到 out 外面，最初 toJSONString 输入的也是 out
                out.append(startSeperator);
            }

            if (getters.length > 0 && out.isEnabled(SerializerFeature.PrettyFormat)) {serializer.incrementIndent();
                serializer.println();}

            boolean commaFlag = false;

            if ((this.beanInfo.features & SerializerFeature.WriteClassName.mask) != 0
                ||(features & SerializerFeature.WriteClassName.mask) != 0
                || serializer.isWriteClassName(fieldType, object)) {Class<?> objClass = object.getClass();

                final Type type;
                if (objClass != fieldType && fieldType instanceof WildcardType) {type = TypeUtils.getClass(fieldType);
                } else {type = fieldType;}

                if (objClass != type) {writeClassName(serializer, beanInfo.typeKey, object);
                    commaFlag = true;
                }
            }

            char seperator = commaFlag ? ',' : '\0';

            final boolean writeClassName = out.isEnabled(SerializerFeature.WriteClassName);
            char newSeperator = this.writeBefore(serializer, object, seperator);
            commaFlag = newSeperator == ',';

            final boolean skipTransient = out.isEnabled(SerializerFeature.SkipTransientField);
            final boolean ignoreNonFieldGetter = out.isEnabled(SerializerFeature.IgnoreNonFieldGetter);

            for (int i = 0; i < getters.length; ++i) {..... 字符串拼接}

            this.writeAfter(serializer, object, commaFlag ? ',' : '\0');

            if (getters.length > 0 && out.isEnabled(SerializerFeature.PrettyFormat)) {serializer.decrementIdent();
                serializer.println();}

            if (!unwrapped) {
                // 全程增加进 out 外面
                out.append(endSeperator);
            }
        } catch (Exception e) {..... 解决异样，疏忽} finally {serializer.context = parent;}
    }