android studio 运行java代码输出乱码问题

在java项目的build.gradle中加入

tasks.withType(JavaCompile) {
    options.encoding = "UTF-8"
}

就好了

apply plugin: 'java-library'

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
}
tasks.withType(JavaCompile) {
    options.encoding = "UTF-8"
}

sourceCompatibility = "1.7"
targetCompatibility = "1.7"