Tips???♂：本文是RookieDB項目的初始環(huán)節(jié)，我們需要配置本地的開發(fā)環(huán)節(jié)，并初步使用test任務進行某個任務修改開發(fā)測試提交的過程，同時我們將需要實現(xiàn)一個非常簡單的bug修改。add ??!

1. getting-started

Logistics

后勤

This assignment is due Monday, 8/29/2022 at 11:59PM PDT (GMT-7). It is worth 0% of your overall grade, but failure to complete it may result in being administratively dropped from the class.

本作業(yè)應于星期一，2022年8月29日11:59PM PDT（GMT-7）。它占你總成績的0%，但如果沒有完成它，可能會導致你被行政上的退學。

Prerequisites

先決條件

No lectures are required to work through this assignment.

在完成這項任務時，不需要講課。

git and GitHub

git is a version control system, that helps developers like you track different versions of your code, synchronize them across different machines, and collaborate with others. If you don't already have git on your machine you can follow the instructions here to install it.

git是一個版本控制系統(tǒng)，它幫助像你這樣的開發(fā)者跟蹤你的代碼的不同版本，在不同的機器上同步它們，并與其他人協(xié)作。如果你的機器上還沒有git，你可以按照說明這里來安裝它。git是一個版本控制系統(tǒng)，它幫助像你這樣的開發(fā)者跟蹤你的代碼的不同版本，在不同的機器上同步它們，并與其他人協(xié)作。如果你的機器上還沒有git，你可以按照說明這里來安裝它。

GitHub is a site which supports this system, hosting it as a service. In order to get a copies of the skeleton code to work on during the semester you'll need to create an account.

GitHub是一個支持這個系統(tǒng)的網(wǎng)站，將其作為一項服務來托管。為了獲得骨架代碼的副本，以便在本學期工作，你需要創(chuàng)建一個賬戶。

We will be using git and GitHub to pass out assignments in this course. If you don't know much about git, that isn't a problem: you will need to use it only in very simple ways that we will show you in order to keep up with class assignments.

我們將使用git和GitHub來傳授本課程的作業(yè)。如果你對git了解不多，那也不是問題：你只需要以非常簡單的方式使用它，我們會告訴你，以便跟上課堂作業(yè)。

If you'd like to use git for managing your own code versioning, there are many guides to using git online -- this is a good one.

如果你想用git來管理你自己的代碼版本，網(wǎng)上有很多使用git的指南 -- 這是一個很好的指南。

Fetching the released code

獲取已發(fā)布的代碼

For each project, we will provide a GitHub Classroom link. Follow the link to create a GitHub repository with the starter code for the project you are working on. Use git clone to get a local copy of the newly created repository. For example, if your GitHub username is oski after being assigned your repo through GitHub Classroom you would run:

git clone https://github.com/cs186-student/fa22-proj0-oski

對于每個項目，我們將提供一個GitHub教室的鏈接。按照該鏈接，為你正在進行的項目創(chuàng)建一個帶有啟動代碼的GitHub倉庫。使用git clone來獲取新創(chuàng)建的倉庫的本地拷貝。例如，如果你的GitHub用戶名是oski，在通過GitHub教室分配給你的倉庫后，你可以運行。

The GitHub Classroom link for this project is provided in the project release post on Edstem.

本項目的GitHub教室鏈接在Edstem上的項目發(fā)布帖中提供。

Debugging Issues with GitHub Classroom

調(diào)試GitHub課堂的問題

Feel free to skip this section if you don't have any issues with GitHub Classroom. If you are having issues (i.e. the page froze or some error message appeared), first check if you have access to your repo at https://github.com/cs186-student/fa22-proj0-username, replacing username with your GitHub username. If you have access to your repo and the starter code is there, then you can proceed as usual.

如果你對GitHub教室沒有任何問題，請隨意跳過這一部分。如果你有問題（即頁面凍結或出現(xiàn)一些錯誤信息），首先檢查你是否可以訪問你的 repo，地址是https://github.com/cs186-student/fa22-proj0-username，用你的GitHub用戶名替換username。如果你能訪問你的 repo，并且啟動代碼也在那里，那么你可以像往常一樣繼續(xù)。

404 Not Found

If you're getting a 404 not found page when trying to access your repo, make sure you've set up your repo using the GitHub Classroom link in the Project 0 release post on Edstem.

如果你在試圖訪問你的 repo 時得到一個 404 not found 頁面，請確保你已經(jīng)使用 Edstem 上項目 0 發(fā)布帖子中的 GitHub 教室鏈接設置了你的 repo。

If you don't have access to your repo at all after following these steps, feel free to contact the course staff on Edstem.

Setting up your local development environment

配置你的本地開發(fā)環(huán)境

You are free to use any text editor or IDE to complete the assignments, but we will build and test your code in a Docker container with Maven.

你可以自由地使用任何文本編輯器或IDE來完成作業(yè)，但我們將在Docker容器中用Maven構建和測試你的代碼。

We recommend setting up a local development environment by installing Java 11 locally (the version our Docker container runs) and using an IDE such as IntelliJ. (Please make sure you have at least Intellij 2019 version, some of the issues from previous semesters are from a too old Intellij)

我們建議通過在本地安裝Java 11（我們的Docker容器運行的版本）和使用IntelliJ等IDE來建立一個本地開發(fā)環(huán)境。(請確保你至少有Intellij 2019版本，前幾個學期的一些問題是由太老的Intellij引起的)

Java 11 downloads (or alternatively, you're free to use OpenJDK)

Java 11下載 (或者，你可以自由使用OpenJDK)

To import the project into IntelliJ, click Open, and select the pom.xml file when importing. pom.xml is what stores the configuration and dependencies you need for the project. Once it is scanned, Maven will use the information in it to build the project for you!

要把項目導入IntelliJ，請點擊打開，導入時選擇pom.xml文件。pom.xml是存儲項目所需配置和依賴關系的文件。一旦掃描到該文件，Maven就會使用其中的信息為你構建該項目。

If launching IntelliJ takes you to an existing workspace instead of showing you the popup above you can open the project by navigating to File -> New -> Project From Existing Sources and then select the pom.xml file and click "OK". "Trust" the project if you are prompted.

如果啟動 IntelliJ 會把你帶到一個現(xiàn)有的工作區(qū)，而不是顯示上面的彈出窗口，你可以通過導航到文件 -> 新建 -> 從現(xiàn)有資源中的項目，然后選擇 pom.xml 文件并點擊 "確定 "來打開該項目。如果有提示，請 "信任 "該項目。

If you previously had used other versions of Java to build project, you can change to Java 11 by File -> Project Structure... -> Change Project SDK to the one you want to use.

如果你以前使用其他版本的Java來構建項目，你可以通過文件->項目結構...改變?yōu)镴ava 11。-> 改變項目SDK到你想使用的版本。

Running tests in IntelliJ

在IntelliJ中運行tests

If you are using IntelliJ and wish to run the tests for a given assignment follow the instructions below.

1. Navigate to one of the test files for the project. For example, for Project 2 navigate to src/java/test/.../index/TestBPlusNode.java.

2. Navigate to one of the tests (as shown below). Click on the green arrow and run the test (it should fail).

如果你使用IntelliJ，并希望為一個特定的任務運行測試，請按照下面的說明進行。

1. 導航到項目的一個測試文件。例如，對于項目2，導航到 src/java/test/.../index/TestBPlusNode.java.&#x20。

2. 導航到其中一個測試（如下圖所示）。點擊綠色箭頭并運行測試（應該會失?。?。

If the green arrow does not appear or you're unable to run the test, follow the steps below.

1. Open up Run/Debug Configurations with Run > Edit Configurations.

2. Click the + button in the top left to create a new configuration, and choose JUnit from the dropdown. Fill in the configurations as shown below and click ok. Make sure to click Modify Options > Search for tests > In whole project.

如果綠色箭頭沒有出現(xiàn)或者你無法運行測試，請按照以下步驟操作。

1. 用Run > Edit Configurations打開Run/Debug Configurations。

2. 點擊左上角的+按鈕，創(chuàng)建一個新的配置，并從下拉菜單中選擇JUnit。如下圖所示填寫配置，然后點擊確定。確保點擊修改選項>搜索測試>在整個項目中。

You should now see Project 2 tests in the dropdown in the top right. You can run/debug this configuration to run all the Project 2 tests.

現(xiàn)在你應該在右上方的下拉菜單中看到項目2的測試。你可以運行/調(diào)試這個配置來運行所有項目2的測試。

If for some reason you still cannot run the tests, it's likely that you had one of the steps above wrong. At this time, the best thing to do is to re-clone the project and go through the setting up again. Some students may try re-importing the pom.xml file, but there could be some configuration being polluted, so the safest option is to re-clone the project and import the pom.xml file again.

如果由于某種原因，你仍然不能運行測試，很可能是你在上面的某個步驟中出了問題。這時，最好的辦法是重新克隆項目并重新進行設置。有些學生可能會嘗試重新導入pom.xml文件，但可能有一些配置被污染了，所以最安全的選擇是重新克隆項目并再次導入pom.xml文件。

Once you have a copy of the released code, head to the next section "Your Tasks" and begin working on the assignment.

一旦你有了一份已發(fā)布的代碼，就前往下一節(jié) "你的任務"，并開始進行作業(yè)。

2.tasks

任務列表

For this assignment you will get acquainted with running RookieDB's command line interface and make a small change to one file to get things working properly.

在這個作業(yè)中，你將熟悉運行RookieDB的命令行界面，并對一個文件進行小的修改，使其正常工作。

Task 1: Running the CLI

任務1：運行命令行界面

Most databases provide a command line interface (CLI) to send and view the results of queries. To run the CLI in IntelliJ navigate to the file:

src/main/java/edu/berkeley/cs186/database/cli/CommandLineInterface

大多數(shù)數(shù)據(jù)庫提供了一個命令行界面（CLI）來發(fā)送和查看查詢的結果。要在IntelliJ中運行CLI，請導航到文件。

It's okay if you don't understand most of the code here right now, we just want to run it. Locate the arrow next to the class declaration click on it to start the CLI.

Note: If you see the warning

如果你現(xiàn)在不理解這里的大部分代碼也沒關系，我們只是想運行它。找到類聲明旁邊的箭頭，點擊它來啟動CLI。

注意：如果你看到警告

Required type: List <edu.berkeley.cs186.database.table.Record>
Provided: List <Record>

It is because you are using a very new version of Java. If you find it concerning to see the red line in Intellij, follow the steps in the previous page to change the Java SDK

這是因為你正在使用一個非常新的Java版本。如果你發(fā)現(xiàn)在Intellij中看到的紅線令人擔憂，請按照前一頁的步驟來改變Java SDK。

This should open a new panel in IntelliJ resembling the following image:

這應該在IntelliJ中打開一個新的面板，類似于下面的圖片。

Click on this panel and try typing in the following query and hitting enter:

SELECT * FROM Courses LIMIT 5;

You should get something similar to the following output:

點擊這個面板，試著輸入以下查詢并點擊回車鍵。

SELECT * FROM Courses LIMIT 5;

你應該得到類似于下面的輸出。

Hmm, that doesn't look quite right! Follow the instructions in the next task to get the proper output. To exit the CLI just type in exit and hit enter.

嗯，這看起來不大對勁! 按照下一個任務中的指示來獲得正確的輸出。要退出CLI，只需鍵入exit并點擊回車。

Task 2: Welcome to CS186!

任務2：歡迎來到CS186

Open up src/main/java/edu/berkeley/cs186/database/databox/StringDataBox.java. It's okay if you do not understand most of the code right now.

The toString method currently looks like:

打開 src/main/java/edu/berkeley/cs186/database/databox/StringDataBox.java。如果你現(xiàn)在不理解大部分的代碼，也沒關系。

toString方法目前看起來如下：

??

Follow the instructions in the TODO(proj0) comment to fix the return statement.

Navigate tosrc/test/java/edu/berkeley/cs186/database/databox/TestWelcome.java and try running the test in the file, which should now be passing. Now you can run through Task 1 again to see what the proper output should be.

(If you see anything highlighted in red in the test file, its likely that JUnit wasn't automatically added to the classpath. If this is the case, find the first failed import and hover over the portion marked in red. This should bring up a tooltip with the option "Add JUnit to classpath". Select this option. Afterwards, no errors should appear in the file.)

按照TODO(proj0)注釋中的指示來修復返回語句。

導航到src/test/java/edu/berkeley/cs186/database/databox/TestWelcome.java并嘗試運行文件中的測試，現(xiàn)在應該是通過的。現(xiàn)在你可以再次運行任務1，看看正確的輸出應該是什么。

(如果你在測試文件中看到任何以紅色突出顯示的東西，它可能是JUnit沒有自動添加到classpath中。如果是這種情況，找到第一個失敗的導入，將鼠標懸停在標為紅色的部分。這應該會彈出一個工具提示，上面有 "將JUnit添加到classpath "的選項。選擇這個選項。之后，文件中不應該出現(xiàn)任何錯誤）。

Task 3: Debugging Exercise

任務3：調(diào)試練習

In this course, a majority of the projects are written in Java and involve modifying a large codebase. Knowing how to effectively utilize the IntelliJ debugger will be important in identifying errors with your code. Let's cover the basics of using the IntelliJ debugger!

在這個課程中，大部分項目都是用Java編寫的，涉及到修改一個大型代碼庫。知道如何有效地利用IntelliJ調(diào)試器，對于識別代碼中的錯誤非常重要。讓我們來介紹一下使用IntelliJ調(diào)試器的基本知識吧!

As you follow along with the steps below, please submit your answers to this Gradescope assignment. You must complete this for full credit.

Let's start by navigating to src/java/test/.../index/TestBPlusNode.java.

當你按照下面的步驟進行操作時，請將你的答案提交給這個Gradescope作業(yè)。你必須完成這個任務以獲得全額學分。

讓我們開始瀏覽 src/java/test/.../index/TestBPlusNode.java.

Breakpoints

斷點

Place a breakpoint as shown below. Breakpoints allow you to select locations in your code where you want the debugger to pause.

放置一個斷點，如下圖所示。斷點允許你在代碼中選擇你希望調(diào)試器暫停的位置。

Running the debugger

運行調(diào)試器

Select the green arrow next to the function header for testFromBytes. In the dropdown menu, click debug. This will open a debugging console at the bottom. The code is currently paused at the line we placed a breakpoint on.

選擇testFromBytes的函數(shù)標題旁邊的綠色箭頭。在下拉菜單中，點擊debug。這將在底部打開一個調(diào)試控制臺。目前，代碼在我們放置斷點的那一行暫停了。

Inspecting variables

檢查變量

Question 1: What is the current size of 'leafKeys'?

問題1："leafKeys "的當前大小是多少？

Step into

單步執(zhí)行

Click on the button shown below to step into the LeafNode constructor.

點擊下面的按鈕，進入LeafNode構造函數(shù)。

Step over

step over：在單步執(zhí)行時，在函數(shù)內(nèi)遇到子函數(shù)時不會進入子函數(shù)內(nèi)單步執(zhí)行，而是將子函數(shù)整個執(zhí)行完再停止，也就是把子函數(shù)整個作為一步。有一點,經(jīng)過我們簡單的調(diào)試,在不存在子函數(shù)的情況下是和step into效果一樣的（簡而言之，越過子函數(shù)，但子函數(shù)會執(zhí)行）。

Click on the button shown below to step forward one line.

點擊下圖所示的按鈕，向前走一行。

Question 2: What is the current size of 'rids'? 問題2：目前 "rids"的數(shù)量是多少？

Resume execution

恢復執(zhí)行

This button allows you to resume execution of your program until it reaches another breakpoint. Don't worry if testFromBytes fails after resuming execution. You won't pass this test until project 2.

這個按鈕允許你恢復程序的執(zhí)行，直到它到達另一個斷點。如果恢復執(zhí)行后testFromBytes失敗，請不要擔心。在項目2之前，你不會通過這個測試。

You're done!