领域方法“无法解析符号”

realm.beginTrasnaction() ,它告诉我Android Studio无法解析符号。

以下是我的代码:

import io.realm.Realm;

public class playerCreator {

Realm realm = Realm.getDefaultInstance();

realm.beginTransaction();

}

这是我的gradle文件:

Gradle项目:

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.5.0'
        classpath "io.realm:realm-gradle-plugin:3.5.0"

    }
}

allprojects {
    repositories {
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

apply plugin: 'com.android.application'
apply plugin: 'realm-android'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.1"

    defaultConfig {
        applicationId "tfdev.avventuratestuale"
        minSdkVersion 18
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:24.1.1'
}

有人知道我如何使用领域吗。beginTransaction()?