GWT编译器[错误]行:类型不匹配:无法将元素类型Object转换为Foo

Question

当我编译我的GWT时，我开始得到一个奇怪的错误。这只会在某些时候发生。

 [java] [ERROR] Line 62: Type mismatch: cannot convert from element type Object to SomeClass

文件中的第62行如下所示

for (SomeClass ans : someAutobeanInterface.getSomeClasses()) {

和someAutobeanInterface.getSomeClasses()

List<SomeClass> getSomeClasses();

someAutobeanInterface是一个GWT AutoBean接口。

我使用的是gwt版本2.5.0

我使用ant编译gwt。

<target name="fetch-gwt-dev">
    <echo>Setting up GWT-dependencies</echo>

    <artifact:dependencies filesetId="gwt-dev.dependencies.classpath">
        <dependency groupId="com.google.gwt" artifactId="gwt-dev" version="2.5.0" />
        <dependency groupId="com.bradrydzewski" artifactId="gwt-cal" version="0.9.3.1" />
        <dependency groupId="com.google.gwt.google-apis" artifactId="gwt-visualization" version="1.0.2" />
    </artifact:dependencies>

    <artifact:dependencies filesetId="gwt-user.dependencies.classpath">
        <dependency groupId="com.google.gwt" artifactId="gwt-user" version="2.5.0" />
        <dependency groupId="javax.validation" artifactId="validation-api" version="1.0.0.GA" classifier="sources" />
    </artifact:dependencies>
</target>

<macrodef name="compilegwtappfast" >
    <!-- XXX This macro is kind of strange since it depends on the target fetch-gwt-dev to have been run -->

    <attribute name="package" />
    <attribute name="fakepackage" />
    <attribute name="outputdir" />
    <!-- The number of workers -->
    <attribute name="numberOfWorkers" />
    <!-- If the app needs some additional entry on the classpath (such as GWT-Widgets, that should be added here) -->
    <element name="additional-classpath" optional="true" />

    <sequential>
        <echo>Compiling GWT app @{package} and putting it in @{outputdir}</echo>
        <echo>Compiling package: @{fakePackage}</echo>

        <!-- This directory isn't in SVN so it's not a problem if it doesn't exist -->
        <delete description="Cleaning compiler output directory" failonerror="false">
            <fileset dir="@{outputdir}">
                <include name="**"/>
            </fileset>
        </delete>

        <java fork="true" classname="com.google.gwt.dev.Compiler" failonerror="true">
            <classpath>
                <fileset refid="gwt-user.dependencies.classpath" />
                <fileset refid="gwt-dev.dependencies.classpath" />
                <filelist dir="${basedir}">
                    <file name="src/main/java/" />
                </filelist>
            </classpath>
            <jvmarg value="-Xmx256M"/>
            <arg line="-localWorkers @{numberOfWorkers}" />
            <arg line="-war @{outputdir}"/>
            <arg value="@{fakepackage}" />
        </java>

        <copy todir="@{outputdir}" description="Move the compiler-output to it's right location" failonerror="true">
            <fileset dir="@{outputdir}/@{package}/">
                <include name="**" />
            </fileset>
        </copy>
        <delete dir="@{outputdir}/@{package}">
        </delete>
    <tstamp>
        <format property="DONE_COMPILING" pattern="yyyy-MM-dd HH:mm:ss"/>  
    </tstamp>  
    <echo>Done compiling GWT-app: ${DONE_COMPILING}</echo>
    </sequential>
</macrodef>

<target name="compile-gwt" depends="fetch-gwt-dev">
    <compilegwtapp package="my.gwt.package" outputdir="${basedir}/src/main/webapp/mygwt/" numberOfWorkers="4"/>
</target>

有谁对如何解决这个问题有什么想法？

Answer 1

eclipse中Java编译器遵从性设置可能存在严重错误。它们可能设置为不允许使用1.5+语法。