dubbo.apache.org/dubbo-go/v3@v3.1.1/filter/generic/generalizer/gson.go (about)

     1  /*
     2   * Licensed to the Apache Software Foundation (ASF) under one or more
     3   * contributor license agreements.  See the NOTICE file distributed with
     4   * this work for additional information regarding copyright ownership.
     5   * The ASF licenses this file to You under the Apache License, Version 2.0
     6   * (the "License"); you may not use this file except in compliance with
     7   * the License.  You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   */
    17  
    18  package generalizer
    19  
    20  import (
    21  	"encoding/json"
    22  	"reflect"
    23  	"sync"
    24  )
    25  
    26  import (
    27  	hessian "github.com/apache/dubbo-go-hessian2"
    28  
    29  	"github.com/dubbogo/gost/log/logger"
    30  
    31  	perrors "github.com/pkg/errors"
    32  )
    33  
    34  import (
    35  	"dubbo.apache.org/dubbo-go/v3/protocol/dubbo/hessian2"
    36  )
    37  
    38  var (
    39  	jsonGeneralizer     Generalizer
    40  	jsonGeneralizerOnce sync.Once
    41  )
    42  
    43  func GetGsonGeneralizer() Generalizer {
    44  	jsonGeneralizerOnce.Do(func() {
    45  		jsonGeneralizer = &GsonGeneralizer{}
    46  	})
    47  	return jsonGeneralizer
    48  }
    49  
    50  type GsonGeneralizer struct{}
    51  
    52  func (GsonGeneralizer) Generalize(obj interface{}) (interface{}, error) {
    53  	newObj, ok := obj.(hessian.POJO)
    54  	if !ok {
    55  		return nil, perrors.Errorf("unexpected type of obj(=%T), wanted is hessian pojo", obj)
    56  	}
    57  
    58  	jsonbytes, err := json.Marshal(newObj)
    59  	if err != nil {
    60  		return nil, err
    61  	}
    62  
    63  	return string(jsonbytes), nil
    64  }
    65  
    66  func (GsonGeneralizer) Realize(obj interface{}, typ reflect.Type) (interface{}, error) {
    67  	jsonbytes, ok := obj.(string)
    68  	if !ok {
    69  		return nil, perrors.Errorf("unexpected type of obj(=%T), wanted is string", obj)
    70  	}
    71  
    72  	// create the target object
    73  	ret, ok := reflect.New(typ).Interface().(hessian.POJO)
    74  	if !ok {
    75  		return nil, perrors.Errorf("the type of obj(=%s) should be hessian pojo", typ)
    76  	}
    77  
    78  	err := json.Unmarshal([]byte(jsonbytes), ret)
    79  	if err != nil {
    80  		return nil, err
    81  	}
    82  
    83  	return ret, nil
    84  }
    85  
    86  func (GsonGeneralizer) GetType(obj interface{}) (typ string, err error) {
    87  	typ, err = hessian2.GetJavaName(obj)
    88  	// no error or error is not NilError
    89  	if err == nil || err != hessian2.NilError {
    90  		return
    91  	}
    92  
    93  	typ = "java.lang.Object"
    94  	if err == hessian2.NilError {
    95  		logger.Debugf("the type of nil object couldn't be inferred, use the default value(\"%s\")", typ)
    96  		return
    97  	}
    98  
    99  	logger.Debugf("the type of object(=%T) couldn't be recognized as a POJO, use the default value(\"%s\")", obj, typ)
   100  	return
   101  }