pyjnius_demo.ipynb

{
  "nbformat": 4,
  "nbformat_minor": 0,
  "metadata": {
    "colab": {
      "name": "pyjnius-demo.ipynb",
      "provenance": [],
      "collapsed_sections": [],
      "include_colab_link": true
    },
    "kernelspec": {
      "name": "python3",
      "display_name": "Python 3"
    }
  },
  "cells": [
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "view-in-github",
        "colab_type": "text"
      },
      "source": [
        "<a href=\"https://colab.research.google.com/github/castorini/anserini-notebooks/blob/master/pyjnius_demo.ipynb\" target=\"_parent\"><img src=\"https://colab.research.google.com/assets/colab-badge.svg\" alt=\"Open In Colab\"/></a>"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "vUpmSFflwzR1",
        "colab_type": "text"
      },
      "source": [
        "# Pyjnius Demo"
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "-2PzgU4YxIl3",
        "colab_type": "text"
      },
      "source": [
        "\n",
        "This notebook provides a brief overview of issues with Pyjnius (version 1.2) connecting to the default JVM on colab (and how to fix), as of November 2019."
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "J5DO3H1GxtIn",
        "colab_type": "code",
        "colab": {}
      },
      "source": [
        "%%capture\n",
        "!pip install pyjnius"
      ],
      "execution_count": 0,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "Iy0TcJMDycNq",
        "colab_type": "text"
      },
      "source": [
        "What version of Java are we running?"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "yGpD4xZ_yWMa",
        "colab_type": "code",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 68
        },
        "outputId": "75cc938a-2edb-494e-aebc-5245cb4b09b9"
      },
      "source": [
        "!java -version"
      ],
      "execution_count": 2,
      "outputs": [
        {
          "output_type": "stream",
          "text": [
            "openjdk version \"11.0.4\" 2019-07-16\n",
            "OpenJDK Runtime Environment (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3)\n",
            "OpenJDK 64-Bit Server VM (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3, mixed mode, sharing)\n"
          ],
          "name": "stdout"
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "f2vNd7bpJlDZ",
        "colab_type": "text"
      },
      "source": [
        "Let's try using pyjnius!"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "Yh8Nsi8kykKX",
        "colab_type": "code",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 477
        },
        "outputId": "3902f872-4cdc-46dd-c0a0-cbb6630518a3"
      },
      "source": [
        "from jnius import autoclass"
      ],
      "execution_count": 3,
      "outputs": [
        {
          "output_type": "error",
          "ename": "KeyError",
          "evalue": "ignored",
          "traceback": [
            "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
            "\u001b[0;31mKeyError\u001b[0m                                  Traceback (most recent call last)",
            "\u001b[0;32m<ipython-input-3-1301a43cafb0>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0;32mfrom\u001b[0m \u001b[0mjnius\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0mautoclass\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
            "\u001b[0;32m/usr/local/lib/python3.6/dist-packages/jnius/__init__.py\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m     11\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     12\u001b[0m \u001b[0;32mfrom\u001b[0m \u001b[0;34m.\u001b[0m\u001b[0mjnius\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0;34m*\u001b[0m  \u001b[0;31m# noqa\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m---> 13\u001b[0;31m \u001b[0;32mfrom\u001b[0m \u001b[0;34m.\u001b[0m\u001b[0mreflect\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0;34m*\u001b[0m  \u001b[0;31m# noqa\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m     14\u001b[0m \u001b[0;32mfrom\u001b[0m \u001b[0msix\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0mwith_metaclass\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     15\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
            "\u001b[0;32m/usr/local/lib/python3.6/dist-packages/jnius/reflect.py\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m     13\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     14\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m---> 15\u001b[0;31m \u001b[0;32mclass\u001b[0m \u001b[0mClass\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mwith_metaclass\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mMetaJavaClass\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mJavaClass\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m     16\u001b[0m     \u001b[0m__javaclass__\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;34m'java/lang/Class'\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     17\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
            "\u001b[0;32m/usr/local/lib/python3.6/dist-packages/six.py\u001b[0m in \u001b[0;36m__new__\u001b[0;34m(cls, name, this_bases, d)\u001b[0m\n\u001b[1;32m    825\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    826\u001b[0m         \u001b[0;32mdef\u001b[0m \u001b[0m__new__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mcls\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mname\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mthis_bases\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0md\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 827\u001b[0;31m             \u001b[0;32mreturn\u001b[0m \u001b[0mmeta\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mname\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mbases\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0md\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    828\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    829\u001b[0m         \u001b[0;34m@\u001b[0m\u001b[0mclassmethod\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_export_class.pxi\u001b[0m in \u001b[0;36mjnius.MetaJavaClass.__new__\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_export_class.pxi\u001b[0m in \u001b[0;36mjnius.MetaJavaClass.resolve_class\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_env.pxi\u001b[0m in \u001b[0;36mjnius.get_jnienv\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_jvm_dlopen.pxi\u001b[0m in \u001b[0;36mjnius.get_platform_jnienv\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_jvm_dlopen.pxi\u001b[0m in \u001b[0;36mjnius.create_jnienv\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32m/usr/lib/python3.6/os.py\u001b[0m in \u001b[0;36m__getitem__\u001b[0;34m(self, key)\u001b[0m\n\u001b[1;32m    667\u001b[0m         \u001b[0;32mexcept\u001b[0m \u001b[0mKeyError\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    668\u001b[0m             \u001b[0;31m# raise KeyError with the original key value\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 669\u001b[0;31m             \u001b[0;32mraise\u001b[0m \u001b[0mKeyError\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mkey\u001b[0m\u001b[0;34m)\u001b[0m \u001b[0;32mfrom\u001b[0m \u001b[0;32mNone\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    670\u001b[0m         \u001b[0;32mreturn\u001b[0m \u001b[0mself\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mdecodevalue\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mvalue\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    671\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
            "\u001b[0;31mKeyError\u001b[0m: 'JAVA_HOME'"
          ]
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "VJth0V8Jy2Ku",
        "colab_type": "text"
      },
      "source": [
        "Ops!"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "E_lt0-pXJia0",
        "colab_type": "code",
        "colab": {}
      },
      "source": [
        "import os\n",
        "os.environ[\"JAVA_HOME\"] = \"/usr/lib/jvm/java-11-openjdk-amd64\""
      ],
      "execution_count": 0,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "mBzJC4bOy6ec",
        "colab_type": "text"
      },
      "source": [
        "Let's try again!"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "cOOjiHNJy1eH",
        "colab_type": "code",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 497
        },
        "outputId": "94e09e6f-b978-4383-c114-a564a39bd72f"
      },
      "source": [
        "from jnius import autoclass"
      ],
      "execution_count": 5,
      "outputs": [
        {
          "output_type": "error",
          "ename": "SystemError",
          "evalue": "ignored",
          "traceback": [
            "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
            "\u001b[0;31mSystemError\u001b[0m                               Traceback (most recent call last)",
            "\u001b[0;32m<ipython-input-5-1301a43cafb0>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0;32mfrom\u001b[0m \u001b[0mjnius\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0mautoclass\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
            "\u001b[0;32m/usr/local/lib/python3.6/dist-packages/jnius/__init__.py\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m     11\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     12\u001b[0m \u001b[0;32mfrom\u001b[0m \u001b[0;34m.\u001b[0m\u001b[0mjnius\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0;34m*\u001b[0m  \u001b[0;31m# noqa\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m---> 13\u001b[0;31m \u001b[0;32mfrom\u001b[0m \u001b[0;34m.\u001b[0m\u001b[0mreflect\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0;34m*\u001b[0m  \u001b[0;31m# noqa\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m     14\u001b[0m \u001b[0;32mfrom\u001b[0m \u001b[0msix\u001b[0m \u001b[0;32mimport\u001b[0m \u001b[0mwith_metaclass\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     15\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
            "\u001b[0;32m/usr/local/lib/python3.6/dist-packages/jnius/reflect.py\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[1;32m     13\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     14\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m---> 15\u001b[0;31m \u001b[0;32mclass\u001b[0m \u001b[0mClass\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mwith_metaclass\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mMetaJavaClass\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mJavaClass\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m     16\u001b[0m     \u001b[0m__javaclass__\u001b[0m \u001b[0;34m=\u001b[0m \u001b[0;34m'java/lang/Class'\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m     17\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n",
            "\u001b[0;32m/usr/local/lib/python3.6/dist-packages/six.py\u001b[0m in \u001b[0;36m__new__\u001b[0;34m(cls, name, this_bases, d)\u001b[0m\n\u001b[1;32m    825\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    826\u001b[0m         \u001b[0;32mdef\u001b[0m \u001b[0m__new__\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mcls\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mname\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mthis_bases\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0md\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m:\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0;32m--> 827\u001b[0;31m             \u001b[0;32mreturn\u001b[0m \u001b[0mmeta\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0mname\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0mbases\u001b[0m\u001b[0;34m,\u001b[0m \u001b[0md\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m\u001b[1;32m    828\u001b[0m \u001b[0;34m\u001b[0m\u001b[0m\n\u001b[1;32m    829\u001b[0m         \u001b[0;34m@\u001b[0m\u001b[0mclassmethod\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_export_class.pxi\u001b[0m in \u001b[0;36mjnius.MetaJavaClass.__new__\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_export_class.pxi\u001b[0m in \u001b[0;36mjnius.MetaJavaClass.resolve_class\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_env.pxi\u001b[0m in \u001b[0;36mjnius.get_jnienv\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_jvm_dlopen.pxi\u001b[0m in \u001b[0;36mjnius.get_platform_jnienv\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;32mjnius/jnius_jvm_dlopen.pxi\u001b[0m in \u001b[0;36mjnius.create_jnienv\u001b[0;34m()\u001b[0m\n",
            "\u001b[0;31mSystemError\u001b[0m: Error calling dlopen(b'/usr/lib/jvm/java-11-openjdk-amd64/jre/lib/amd64/server/libjvm.so': b'/usr/lib/jvm/java-11-openjdk-amd64/jre/lib/amd64/server/libjvm.so: cannot open shared object file: No such file or directory'"
          ]
        }
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "TwSMvuMb2EJq",
        "colab_type": "text"
      },
      "source": [
        "This is the fix:"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "O2b5X0hx1pvy",
        "colab_type": "code",
        "colab": {}
      },
      "source": [
        "%%capture\n",
        "\n",
        "!mkdir -p /usr/lib/jvm/java-1.11.0-openjdk-amd64/jre/lib/amd64/server/\n",
        "!ln -s /usr/lib/jvm/java-1.11.0-openjdk-amd64/lib/server/libjvm.so /usr/lib/jvm/java-1.11.0-openjdk-amd64/jre/lib/amd64/server/libjvm.so"
      ],
      "execution_count": 0,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "xbXmstbGypef",
        "colab_type": "text"
      },
      "source": [
        "And we're good:"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "JT_OJKftdqGP",
        "colab_type": "code",
        "colab": {
          "base_uri": "https://localhost:8080/",
          "height": 34
        },
        "outputId": "b24db00a-9bf9-4482-e4be-75607b996049"
      },
      "source": [
        "from jnius import autoclass\n",
        "\n",
        "JString = autoclass('java.lang.String')\n",
        "JString('Hello world')"
      ],
      "execution_count": 7,
      "outputs": [
        {
          "output_type": "execute_result",
          "data": {
            "text/plain": [
              "<java.lang.String at 0x7f6a80a632b0 jclass=java/lang/String jself=<LocalRef obj=0x31060d0 at 0x7f6a81a167f0>>"
            ]
          },
          "metadata": {
            "tags": []
          },
          "execution_count": 7
        }
      ]
    }
  ]
}