-source 1.3不支持泛型

Question

I have a problem while maven packaging. In this code:

public class LoginDialog extends Dialog {

    private final TextField<String> customer;
                          ^here
    private final TextField<String> login1;
    private final TextField<String> password1;
    private final MainController controller= new MainController();
    private String customerId;
    private String login;
    private String password;

I have an error like:

[ERROR] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Compilation failure
...src/main/java/com/messagedna/web/client/widget/LoginDialog.java:[19,27] error: generics are not supported in -source 1.3

what may be the reason of this?

Answer 1

Generics were added in java 1.5. Your maven is compiling for java 1.3.

This can be fixed in one of two ways.

Remove generics so that you can compile for < 1.5

Change the maven configuration to compile for a newer version of java. You should be able to edit your compiler plugin in your pom:

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.0</version>
            <configuration>
                <source>1.5</source>
                <target>1.5</target>
            </configuration>
        </plugin>

This tells maven to compile for 1.5

Answer 2

You need to tell the maven compiler plugin that your code is using a recent java version. For instance, if you are using java 7, to the following:

<plugins>
   <plugin>
     <groupId>org.apache.maven.plugins</groupId>
     <artifactId>maven-compiler-plugin</artifactId>
     <configuration>
       <source>1.7</source>
       <target>1.7</target>
     </configuration>
   </plugin>
</plugins>

Answer 3

使用-source 1.3编译代码时，编译器不支持JDK 1.3之后引入的断言，泛型或其他语言功能。

Answer 4

您要么需要更改设置，以便将源设置为1.5+，要么从代码中删除泛型：

private final TextField customer;

Answer 5

Generics were only introduced as a feature in Java 5, so when compiling using 3, generics will not be permitted. If you want more info about generics, look here . So you need to either compile using 5 or later or stop using generics.

Answer 6

Android studio: It fixes by adding these below lines in the file app build.gradle

compileOptions { sourceCompatibility JavaVersion.VERSION_1_8 targetCompatibility JavaVersion.VERSION_1_8 }

Note: use the latest java version, here I'm using java 8

Answer 7

If you are not using maven and facing similar issue in Intellij editor, probably worth to check Project Settings. Even if you define Proper JDK, change the "Project language level" and can configure 5 onward.