java - Java 中使用 XStream 时出现 NoSuchMethodError

Question

我正在尝试使用 XStream 将数据库保存到文件中，然后稍后使用 XStream 再次打开它，并将其反序列化回之前所在的对象。数据库由表的数组列表组成，表的数组列表由数据类的数组列表组成，其中数据类包含对象的数组列表。我基本上是想创建一个 sql 编译器。由于 load 方法中的最后一行，我目前收到 java.lang.NoSuchMethodError 。这是我所拥有的:

保存方法

    public void save(Database DB){
    File file = new File(DB.getName().toUpperCase() + ".xml");

    //Test sample
    DB.createTable("TBL1(character(a));");
    DB.tables.getTable("TBL1").rows.add(new DataList());
    DB.tables.getTable("TBL1").rows.getRow(0).add(10);

    XStream xstream = new XStream();
    //Database
    xstream.alias("Database", Database.class);
    //Tables
    xstream.alias("Table", Table.class);
    //Rows
    xstream.alias("Row", DataList.class);
    //Data
    //xstream.alias("Data", Object.class);

    //String xml = xstream.toXML(DB);
    Writer writer = null;
    try {
        writer = new FileWriter(file);
        writer.write(xstream.toXML(DB));
        writer.close();
    } catch (IOException e) {
        e.printStackTrace();
    }        
}

加载方法

public void Load(String dbName){
    XStream xstream = new XStream();

    BufferedReader br;
    StringBuffer buff = null;
    try {
        br = new BufferedReader(new FileReader(dbName + ".xml"));
        buff = new StringBuffer();
        String line;
        while((line = br.readLine()) != null){
           buff.append(line);
        }
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    database = (Database)xstream.fromXML(buff.toString());
}

堆栈跟踪

Exception in thread "main" java.lang.NoSuchMethodError:     
org.xmlpull.v1.XmlPullParserFactory.newInstance(Ljava/lang/String;Ljava/lang/Class;)Lorg/xmlpull/v1/XmlPullParserFactory;
at com.thoughtworks.xstream.io.xml.XppDriver.createParser(XppDriver.java:57)
at com.thoughtworks.xstream.io.xml.AbstractXppDriver.createReader(AbstractXppDriver.java:54)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:913)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:904)
at dbt.Load(dbt.java:255)
at dbt.checktypestatement(dbt.java:88)
at dbt.main(dbt.java:45)

更改一些库(引用库:xstream、xpp3 和 xmlpull)后，这是我在运行时遇到的错误:

Exception in thread "main" com.thoughtworks.xstream.converters.ConversionException: Row : Row
---- Debugging information ----
message             : Row
cause-exception     : com.thoughtworks.xstream.mapper.CannotResolveClassException
cause-message       : Row
class               : java.util.ArrayList
required-type       : java.util.ArrayList
converter-type      : com.thoughtworks.xstream.converters.collections.CollectionConverter
path                : /Database/tables/tables/Table/rows/rows/Row
line number         : 1
class[1]            : RowList
converter-type[1]   : com.thoughtworks.xstream.converters.reflection.ReflectionConverter
class[2]            : Table
class[3]            : TableList
class[4]            : Database
version             : null
-------------------------------
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:79)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshallField(AbstractReflectionConverter.java:355)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doUnmarshal(AbstractReflectionConverter.java:306)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshal(AbstractReflectionConverter.java:234)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshallField(AbstractReflectionConverter.java:355)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doUnmarshal(AbstractReflectionConverter.java:306)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshal(AbstractReflectionConverter.java:234)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readItem(AbstractCollectionConverter.java:71)
at com.thoughtworks.xstream.converters.collections.CollectionConverter.addCurrentElementToCollection(CollectionConverter.java:79)
at com.thoughtworks.xstream.converters.collections.CollectionConverter.populateCollection(CollectionConverter.java:72)
at com.thoughtworks.xstream.converters.collections.CollectionConverter.populateCollection(CollectionConverter.java:66)
at com.thoughtworks.xstream.converters.collections.CollectionConverter.unmarshal(CollectionConverter.java:61)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshallField(AbstractReflectionConverter.java:355)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doUnmarshal(AbstractReflectionConverter.java:306)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshal(AbstractReflectionConverter.java:234)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshallField(AbstractReflectionConverter.java:355)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.doUnmarshal(AbstractReflectionConverter.java:306)
at com.thoughtworks.xstream.converters.reflection.AbstractReflectionConverter.unmarshal(AbstractReflectionConverter.java:234)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134)
at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1058)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1042)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:913)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:904)
at dbt.load(dbt.java:257)
at dbt.checktypestatement(dbt.java:87)
at dbt.main(dbt.java:44)
Caused by: com.thoughtworks.xstream.mapper.CannotResolveClassException: Row
at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:56)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:55)

...

Answer 1

我能够通过注释掉 save 方法中的 xstream.alias 方法来解决该问题。