Running ‘testthat.R’ [6s/13s]
Running the tests in ‘tests/testthat.R’ failed.
Complete output:
  > library(testthat)
  > library(J4R)
  > 
  > test_check("J4R")
  socket error: Connection refused
  ── 1. Error: (unknown) (@testDynamicClasspath.R#14)  ───────────────────────────
  socket not established
  Backtrace:
   1. J4R::connectToJava()
   3. utils::make.socket("localhost", port)
  
  Exception in thread "main" java.lang.UnsupportedClassVersionError: j4r/lang/codetranslator/REnvironment : Unsupported major.minor version 52.0
  	at java.lang.ClassLoader.defineClass1(Native Method)
  	at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
  	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
  	at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
  	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  	at java.security.AccessController.doPrivileged(Native Method)
  	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
  	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
  	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
  	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
  	at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
  Exception in thread "main" java.lang.UnsupportedClassVersionError: j4r/lang/codetranslator/REnvironment : Unsupported major.minor version 52.0
  	at java.lang.ClassLoader.defineClass1(Native Method)
  	at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
  	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
  	at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
  	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  	at java.security.AccessController.doPrivileged(Native Method)
  	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
  	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
  	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
  	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
  	at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
  socket error: Connection refused
  ── 2. Error: (unknown) (@testJavaConnection.R#13)  ─────────────────────────────
  socket not established
  Backtrace:
   1. J4R::connectToJava(...)
   3. utils::make.socket("localhost", port)
  
  Exception in thread "main" java.lang.UnsupportedClassVersionError: j4r/lang/codetranslator/REnvironment : Unsupported major.minor version 52.0
  	at java.lang.ClassLoader.defineClass1(Native Method)
  	at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
  	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
  	at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
  	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  	at java.security.AccessController.doPrivileged(Native Method)
  	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
  	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
  	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
  	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
  	at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
  socket error: Connection refused
  ── 3. Error: (unknown) (@testPerformances.R#12)  ───────────────────────────────
  socket not established
  Backtrace:
   1. J4R::connectToJava()
   3. utils::make.socket("localhost", port)
  
  Exception in thread "main" java.lang.UnsupportedClassVersionError: j4r/lang/codetranslator/REnvironment : Unsupported major.minor version 52.0
  	at java.lang.ClassLoader.defineClass1(Native Method)
  	at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
  	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
  	at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
  	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
  	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  	at java.security.AccessController.doPrivileged(Native Method)
  	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
  	at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
  	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
  	at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
  	at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
  socket error: Connection refused
  ── 4. Error: (unknown) (@testSimple.R#14)  ─────────────────────────────────────
  socket not established
  Backtrace:
   1. J4R::connectToJava()
   3. utils::make.socket("localhost", port)
  
  ══ testthat results  ═══════════════════════════════════════════════════════════
  [ OK: 0 | SKIPPED: 0 | WARNINGS: 0 | FAILED: 4 ]
  1. Error: (unknown) (@testDynamicClasspath.R#14) 
  2. Error: (unknown) (@testJavaConnection.R#13) 
  3. Error: (unknown) (@testPerformances.R#12) 
  4. Error: (unknown) (@testSimple.R#14) 
  
  Error: testthat unit tests failed
  Execution halted