How to fix "import com.dyuproject cannot be resolved" error

Question

I'm fairly new to Java and especially new to Maven and specifically the protostuff project (protostuff website). I need to use protostuff to serialize/deserialize XML to google's protobuf format. I tried using the protobuf-java-format package, but there's a documented error in deserialization that is a show-stopper for me (issue 37).

So far I've done the following:

1. Downloaded protostuff-1.3.1 & extracted it.
2. Ran mvn integration-test, mvn install and mvn packageand all steps succeeded.
3. I then created a new maven project and included a proto as described here

4. I then modified my pom.xml and ran protostuff:compile on the proto as described in the aforementioned link, generating the following Person.java file

   // Generated by http://code.google.com/p/protostuff/ ... DO NOT EDIT!
   // Generated from foo.proto
   
   package com.example.foo;
   
   import java.io.Externalizable;
   import java.io.IOException;
   import java.io.ObjectInput;
   import java.io.ObjectOutput;
   
   import com.dyuproject.protostuff.ByteString;
   import com.dyuproject.protostuff.GraphIOUtil;
   import com.dyuproject.protostuff.Input;
   import com.dyuproject.protostuff.Message;
   import com.dyuproject.protostuff.Output;
   import com.dyuproject.protostuff.Schema;
   import com.dyuproject.protostuff.UninitializedMessageException;
   
   public final class Person implements Externalizable, Message<Person>, Schema<Person>
   {
       public enum Gender implements com.dyuproject.protostuff.EnumLite<Gender>
       {
           MALE(1),
           FEMALE(2);
   
           public final int number;
   
           private Gender (int number)
           {
               this.number = number;
           }
   
           public int getNumber()
           {
               return number;
           }
   
           public static Gender valueOf(int number)
           {
               switch(number) 
               {
                   case 1: return MALE;
                   case 2: return FEMALE;
                   default: return null;
               }
           }
       }
   
   
       public static Schema<Person> getSchema()
       {
           return DEFAULT_INSTANCE;
       }
   
       public static Person getDefaultInstance()
       {
           return DEFAULT_INSTANCE;
       }
   
       static final Person DEFAULT_INSTANCE = new Person();
   
       static final String DEFAULT_MOTTO = ByteString.stringDefaultValue("When the cat is away, the mouse is alone!");
       static final Gender DEFAULT_GENDER = Gender.MALE;
   
       private Integer id;
       private String name;
       private String motto = DEFAULT_MOTTO;
       private Gender gender;
   
       public Person()
       {
   
       }
   
       public Person(
           Integer id
       )
       {
           this.id = id;
       }
   
       // getters and setters
   
       // id
   
       public Integer getId()
       {
           return id;
       }
   
       public void setId(Integer id)
       {
           this.id = id;
       }
   
       // name
   
       public String getName()
       {
           return name;
       }
   
       public void setName(String name)
       {
           this.name = name;
       }
   
       // motto
   
       public String getMotto()
       {
           return motto;
       }
   
       public void setMotto(String motto)
       {
           this.motto = motto;
       }
   
       // gender
   
       public Gender getGender()
       {
           return gender == null ? Gender.MALE : gender;
       }
   
       public void setGender(Gender gender)
       {
           this.gender = gender;
       }
   
       // java serialization
   
       public void readExternal(ObjectInput in) throws IOException
       {
           GraphIOUtil.mergeDelimitedFrom(in, this, this);
       }
   
       public void writeExternal(ObjectOutput out) throws IOException
       {
           GraphIOUtil.writeDelimitedTo(out, this, this);
       }
   
       // message method
   
       public Schema<Person> cachedSchema()
       {
           return this;
       }
   
       // schema methods
   
       public Person newMessage()
       {
           return new Person();
       }
   
       public Class<Person> typeClass()
       {
           return Person.class;
       }
   
       public String messageName()
       {
           return Person.class.getSimpleName();
       }
   
       public String messageFullName()
       {
           return Person.class.getName();
       }
   
       public boolean isInitialized(Person message)
       {
           return 
               message.id != null;
       }
   
       public void mergeFrom(Input input, Person message) throws IOException
       {
           for(int number = input.readFieldNumber(this);; number = input.readFieldNumber(this))
           {
               switch(number)
               {
                   case 0:
                       return;
                   case 1:
                       message.id = input.readInt32();
                       break;
                   case 2:
                       message.name = input.readString();
                       break;
                   case 3:
                       message.motto = input.readString();
                       break;
                   case 4:
                       message.gender = Gender.valueOf(input.readEnum());
                       break;
                   default:
                       input.handleUnknownField(number, this);
               }   
           }
       }
   
   
       public void writeTo(Output output, Person message) throws IOException
       {
           if(message.id == null)
               throw new UninitializedMessageException(message);
           output.writeInt32(1, message.id, false);
   
           if(message.name != null)
               output.writeString(2, message.name, false);
   
           if(message.motto != null && message.motto != DEFAULT_MOTTO)
               output.writeString(3, message.motto, false);
   
           if(message.gender != null)
                output.writeEnum(4, message.gender.number, false);
       }
   
       public String getFieldName(int number)
       {
           switch(number)
           {
               case 1: return "id";
               case 2: return "name";
               case 3: return "motto";
               case 4: return "gender";
               default: return null;
           }
       }
   
       public int getFieldNumber(String name)
       {
           final Integer number = __fieldMap.get(name);
           return number == null ? 0 : number.intValue();
       }
   
       private static final java.util.HashMap<String,Integer> __fieldMap = new java.util.HashMap<String,Integer>();
       static
       {
           __fieldMap.put("id", 1);
           __fieldMap.put("name", 2);
           __fieldMap.put("motto", 3);
           __fieldMap.put("gender", 4);
       }
   
   }
   

I'm building this whole project in Eclipse (Luna release) and it gives the error "import com.dyuproject cannot be resolved" for the above file. I don't understand why it gives the error or how to find/install the package so Eclipse can see it. Should Maven have built/provided that?

I'm running CentOS release 6.4 (Final) on a VirtualBox VM:

uname -a Linux localhost.localdomain 2.6.32-358.18.1.el6.x86_64 #1 SMP Wed Aug 28 17:19:38 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux `

Answer 1

Looks like you are using incompatible protostuff-core and protostuff-maven-plugin versions.

Starting from version 1.1, protostuff uses package io.protostuff instead of com.dyuproject.protostuff. Protostuff dependency version and protostuff maven plugin version should be equal (1.3.5 is the latest version).

Here is an example of maven project that uses protostuff-maven-plugin for code generation.