感觉 golang 比 Java 还难读, 难学

要解析的 json, 格式不完美. 比如

[{ "name": "Abyssin", "price": 500, "location": "Lviv", "image": "https://olxua-ring02.akamaized.net/images_slandocomua/476948786_2_1000x700_abissenysh-chempion-fotografii.jpg" }, { "name": "Abyssin", "price": "550", "location": "Lviv", "image": "https://olxua-ring10.akamaized.net/images_slandocomua/342850976_3_1000x700_abidetki-koti_rev006.jpg" }] 

price 实际上是个 int 但是有些值是 string. 加 tag 就没啥用了, 只能自己写 UnmarshalJSON

好奇看了一下

json/decode

// indirect walks down v allocating pointers as needed, // until it gets to a non-pointer. // If it encounters an Unmarshaler, indirect stops and returns that. // If decodingNull is true, indirect stops at the first settable pointer so it // can be set to nil. func indirect(v reflect.Value, decodingNull bool) (Unmarshaler, encoding.TextUnmarshaler, reflect.Value) { // Issue #24153 indicates that it is generally not a guaranteed property // that you may round-trip a reflect.Value by calling Value.Addr().Elem() // and expect the value to still be settable for values derived from // unexported embedded struct fields. // // The logic below effectively does this when it first addresses the value // (to satisfy possible pointer methods) and continues to dereference // subsequent pointers as necessary. // // After the first round-trip, we set v back to the original value to // preserve the original RW flags contained in reflect.Value. v0 := v haveAddr := false // If v is a named type and is addressable, // start with its address, so that if the type has pointer methods, // we find them. if v.Kind() != reflect.Pointer && v.Type().Name() != "" && v.CanAddr() { haveAddr = true v = v.Addr() } for { // Load value from interface, but only if the result will be // usefully addressable. if v.Kind() == reflect.Interface && !v.IsNil() { e := v.Elem() if e.Kind() == reflect.Pointer && !e.IsNil() && (!decodingNull || e.Elem().Kind() == reflect.Pointer) { haveAddr = false v = e continue } } if v.Kind() != reflect.Pointer { break } if decodingNull && v.CanSet() { break } // Prevent infinite loop if v is an interface pointing to its own address: // var v interface{} // v = &v if v.Elem().Kind() == reflect.Interface && v.Elem().Elem() == v { v = v.Elem() break } if v.IsNil() { v.Set(reflect.New(v.Type().Elem())) } if v.Type().NumMethod() > 0 && v.CanInterface() { if u, ok := v.Interface().(Unmarshaler); ok { return u, nil, reflect.Value{} } if !decodingNull { if u, ok := v.Interface().(encoding.TextUnmarshaler); ok { return nil, u, reflect.Value{} } } } if haveAddr { v = v0 // restore original value after round-trip Value.Addr().Elem() haveAddr = false } else { v = v.Elem() } } return nil, nil, v } 

感觉 java 感觉清爽很多. java 感觉不需要学, 看看 ArrayList HashMap 这些接口就可以写了,语法也比较简单. golang 真是各种奇技淫巧满天飞.