POM Java 7到Java 8

Question

我有一个非常老的项目。那有Java7。我想至少将其上传到Java 8，但我不知道从哪里开始。

如果我直接放置Java 8，它不会消失。

由于该项目正在生产中，所以我希望尽可能地逐步上传版本。

对我有帮助吗？

或者有人可以帮助我如何上传依赖项的版本，以最终掌握Java 8？

如何逐步地做到这一点

我完全迷路了，不知道从哪里开始。

    <java.version>7</java.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

    <aspectj.version>1.7.3</aspectj.version>
    <atmosphere.version>2.2.2</atmosphere.version>
    <birt.version>4.2.2</birt.version>
    <c3p0.version>0.9.1.2</c3p0.version>
    <cglib.version>2.2</cglib.version>
    <cors.version>1.3.2</cors.version>
    <dbunit.version>2.4.9</dbunit.version>
    <equalsverifier.version>1.3.1</equalsverifier.version>
    <flyway.version>2.2.1</flyway.version>
    <gson.version>2.2.4</gson.version>
    <hibernate.version>4.2.19.Final</hibernate.version>
    <hibernate.jpamodelgen.version>1.2.0.Final</hibernate.jpamodelgen.version>
    <hibernate.validator.version>4.3.1.Final</hibernate.validator.version>
    <hsqldb.version>2.3.1</hsqldb.version>
    <httpclient.version>4.3.1</httpclient.version>
    <itext.version>2.1.7</itext.version>
    <jackson.version>2.1.5</jackson.version>
    <jadira.version>3.0.0.GA</jadira.version>
    <jasper.version>5.5.0</jasper.version>
    <javax.faces.version>2.2.2</javax.faces.version>
    <jetty.version>8.1.10.v20130312</jetty.version>
    <joda.version>2.3</joda.version>
    <junit.version>4.11</junit.version>
    <log4j.version>1.2.17</log4j.version>
    <mockito.version>1.9.5</mockito.version>
    <poi.version>3.11</poi.version>
    <postgresql.version>9.2-1002-jdbc4</postgresql.version>
    <powermock.version>1.5.2</powermock.version>
    <primefaces.version>5.2</primefaces.version>
    <primefaces.mobile.version>0.9.4</primefaces.mobile.version>
    <primefaces.extensions.version>3.2.0</primefaces.extensions.version>
    <primefaces.themes.version>1.0.10</primefaces.themes.version>
    <selenium.version>2.36.0</selenium.version>
    <servlet-api.version>2.5</servlet-api.version>
    <slf4j.version>1.7.5</slf4j.version>
    <spring.version>3.2.5.RELEASE</spring.version>
    <spring.data.jpa.version>1.4.2.RELEASE</spring.data.jpa.version>
    <spring.integration.version>3.0.1.RELEASE</spring.integration.version>
    <spring.security.version>3.1.4.RELEASE</spring.security.version>
    <xerces.version>2.9.0</xerces.version>