這是歷史版本頁面 — 看 Java Development Kit (32-bit) 最新版本
舊電腦想寫Java程式,JDK 32位元版夠用嗎
你手上有一台比較舊的 Windows 電腦,可能是七、八年前的機器,系統還停在 Windows 7 或 Windows 8。最近想開始學寫 Java,或是有個舊專案需要重新編譯,於是上網找開發工具,結果發現 Java 的開發套件有分 32 位元和 64 位元,下載頁面全是英文,一時間不知道該選哪一個。裝錯版本怕跑不動,不裝又沒辦法繼續下一步,就這樣卡在下載頁面半小時。
一般人的直覺是「直接抓最新版、最大的那個檔案就對了」,但舊電腦的作業系統和處理器不一定支援 64 位元,硬裝上去可能連安裝程式都打不開。就算安裝成功,也可能因為記憶體不足或系統不相容而頻頻出錯。這類開發工具套件的切入點,其實是讓你在「寫程式」和「執行程式」之間有一整套工具可以用——編譯、打包、除錯、產生說明文件,而不是只給你一個能跑 Java 的環境。搞清楚自己到底需要「開發」還是只要「執行」,才不會裝了一堆用不到的東西。
01JDK 32位元版到底能拿來做什麼?
它是一整套 Java 開發工具,包含編譯器 javac,可以把寫好的 .java 原始碼編譯成 .class 位元碼;jar 工具負責把多個 class 檔打包成一個 JAR 檔案;javadoc 可以從程式碼註解自動產生 API 說明文件;jdb 是除錯器,讓你可以逐步執行程式、檢查變數值。另外它也內建一個完整的 Java 執行環境(JRE),所以開發完的程式可以直接在本機跑。
02它跟 JRE 有什麼不同?我是不是裝 JRE 就夠了?
JRE 只有 Java 虛擬機(JVM)和執行時需要的類別庫,讓你可以「執行」已經編譯好的 Java 程式,但不能自己寫程式碼再編譯。JDK 除了包含完整的 JRE,還多了編譯器、除錯器、打包工具等開發用的程式。如果你只是要跑別人寫好的 Java 應用程式或遊戲,裝 JRE 就夠;如果你要自己寫程式、編譯、打包,才需要 JDK。
03用這套軟體寫 Java 程式,需要另外裝 IDE 嗎?
不需要,但建議裝。JDK 本身是命令列工具,你可以在記事本寫好程式碼,然後打開命令提示字元,用 javac 編譯、用 java 執行,全部靠打字完成。但這樣寫程式很沒效率,官方說明中也提到,開發者通常會搭配 Eclipse、IntelliJ IDEA 或 NetBeans 這類整合開發環境使用,IDE 提供程式碼編輯器、專案管理、一鍵編譯和除錯介面,會比純命令列順手很多。
04安裝完之後怎麼確認有沒有裝好?
安裝完成後,打開命令提示字元(在 Windows 搜尋列輸入 cmd),輸入 java -version 再按 Enter。如果安裝正確,畫面上會顯示 JDK 的版本資訊;如果出現「無法辨識」或「不是內部或外部指令」的訊息,代表安裝路徑沒有正確設定,或是安裝過程有問題。官方安裝說明也特別提到用這個指令來驗證,這是第一個該做的檢查。
05它能不能編譯其他語言寫的程式?
不行。這套軟體是專門給 Java 用的,編譯器 javac 只接受 Java 原始碼,jar 打包的也是 Java 的類別檔。官方功能說明中提到的工具,包含 javac、jar、javadoc、jdb、jshell,全部都是圍繞 Java 生態系設計的。如果你要寫 C、Python 或 JavaScript,需要另外找對應的編譯器或直譯器,這套軟體幫不上忙。
06我的電腦是 32 位元的 Windows,裝這套軟體跑得動嗎?
這套軟體就是設計給 32 位元系統用的,支援 Windows 7、Windows 8 和 Windows 10,所以只要你的系統是這幾個版本之一,理論上可以安裝。不過官方資料沒有提到最低硬體需求,如果你的電腦記憶體低於 2GB,編譯大型專案時可能會比較慢。建議先安裝,用 java -version 確認能跑,再實際編譯一個小程式測試看看。
07初學者用這套軟體學 Java 會不會太難?
官方說明提到 JDK 適合從初學者到專業開發者各種程度的人使用,因為它提供完整的文件、教學和範例程式碼。但它的操作介面是命令列,沒有圖形化按鈕,對完全沒碰過程式的人來說,第一步會比較辛苦。如果你是完全新手,建議搭配一個 IDE(例如 NetBeans)一起用,IDE 會幫你處理很多指令細節,你只要專注在寫程式邏輯就好。
08只是要執行 Java 遊戲或軟體,需要裝這個嗎?
不需要。JDK 是開發工具,裡面雖然包含執行環境,但體積比較大,安裝也比較複雜。如果你只是要跑別人寫好的 Java 程式,安裝 Java Runtime Environment(JRE)就夠了,它只有虛擬機和執行所需的類別庫,輕量很多。官方資料中 JRE 的使用者評分人數有 3861 人,比 JDK 的 1110 人多,也反映多數人其實只需要執行環境。
09我的電腦是 64 位元,裝 32 位元版會有問題嗎?
官方資料沒有提到 64 位元系統安裝 32 位元版會發生什麼事,這部分需要你自己確認。一般來說,64 位元 Windows 可以執行 32 位元應用程式,但效能上可能不如原生 64 位元版本。如果你的系統是 64 位元,建議先到 Oracle 官方下載頁面看看有沒有提供 64 位元版本,有的話優先選那個,記憶體使用效率會比較好。
10公司要拿來開發商用 Java 專案,用這套軟體授權上要注意什麼?
官方說明明確寫著 JDK 可以免費下載和使用,但「商業使用」必須遵守 Oracle 的授權條款。官方文件也提到,商業使用的授權條款可能比較複雜,甚至可能需要付費。如果你的公司要用在商業產品上,建議直接到 Oracle 官方網站查閱最新的 Oracle Technology Network License Agreement,或諮詢法務人員,不要假設免費下載就等於可以任意商用。
11介面只有英文,看不懂操作選項怎麼辦?
這套軟體的介面語系確實只有英文,官方文件、安裝程式和工具輸出都是英文。不過它的核心工具都是命令列指令,常用的只有 javac、java、jar 這幾個,指令參數不多,上網搜尋都有中文教學。安裝過程也只有幾個下一步按鈕,不太會卡住。如果你連安裝程式的英文都覺得吃力,可以找網路上中文的 JDK 安裝教學,照著步驟點就可以了。
12這套軟體跟 OpenJDK 比起來哪個比較好?
官方資料中沒有提到 OpenJDK,所以無法直接比較。JDK 是 Oracle 發行的版本,OpenJDK 是開源社群維護的版本,兩者功能上很接近,但授權條款不同。如果你在意的是商業使用授權,OpenJDK 的授權通常比較寬鬆;如果你想要 Oracle 官方支援和文件,就選 JDK。建議根據你的用途(個人學習還是商業開發)和授權需求,分別到官方網站查閱條款後再決定。
下載與官方連結
前往官方網站 下載 Java Development Kit (32-bit)
jdk-8u141-windows-i586.exe · 190.95 MB · 連結指向軟體原廠
版本紀錄
- 2026-10-26 Java JDK 8 Update 511 (32-bit) 124.17 MB
- 2026-08-20 Java JDK 8 Update 503 (32-bit) 153.44 MB
- 2026-07-27 Java JDK 8 Update 501 (32-bit) 153.46 MB
再看 5 筆
- 2026-04-22 Java JDK 8 Update 491 (32-bit) 153.42 MB
- 2026-03-18 Java JDK 8 Update 481 (32-bit) 87.89 MB
- 2025-07-16 Java JDK 8 Update 461 (32-bit) 87.01 MB
- 2025-04-16 Java JDK 8 Update 451 (32-bit) 86.98 MB
- 2025-01-22 Java JDK 8 Update 441 (32-bit) 143.35 MB
這一版改了什麼
What's new in this version:
IANA DATA 2017b:
- JDK 8u141 contains IANA time zone data version 2017b
CERTIFICATE CHANGES:
- Let's Encrypt certificates added to root CAs. One new root certificate has been added
NEW FEATURES:
security-libs/java.security. Improved algorithm constraints checking:
- With the need to restrict weak algorithms usage in situations where they are most vulnerable, additional features have been added when configuring the jdk.certpath.disabledAlgorithms and jdk.jar.disabledAlgorithms security properties in the java.security file.
- jdk.certpath.disabledAlgorithms: The certpath property has seen the most change. Previously it was limited to two Constraint types; either a full disabling of an algorithm by name or a full disabling of an algorithm by the key size when checking certificates, certificate chains, and certificate signatures. This creates configurations that are absolute and lack flexibility in their usage. Three new Constraints were added to give more flexibility in allowing and rejecting certificates.
- "jdkCA" examines the certificate chain termination with regard to the cacerts file. In the case of "SHA1 jdkCA". SHA1's usage is checked through the certificate chain, but the chain must terminate at a marked trust anchor in the cacerts keystore to be rejected. This is useful for organizations that have their own private CA that trust using SHA1 with their trust anchor, but want to block certificate chains anchored by a public CA from using SHA1.
- "denyAfter" checks if the given date is before the current date or the PKIXParameter date. In the case of "SHA1 denyAfter 2018-01-01", before 2018 a certificate with SHA1 can be used, but after that date, the certificate is rejected. This can be used for a policy across an organization that is phasing out an algorithm with a drop-dead date. For signed JAR files, the date is compared against the TSA timestamp. The date is specified in GMT.
"usage" examines the specified algorithm for a specified usage. This can be used when disabling an algorithm for all usages is not practical. There are three usages that can be specified:
- TLSServer' restricts the algorithm in TLS server certificate chains when server authentication is performed as a client
- TLSClient' restricts the algorithm in TLS client certificate chains when client authentication is performed as a server
- SignedJAR' restricts the algorithms in certificates in signed JAR files. The usage type follows the keyword and more than one usage type can be specified with a whitespace delimiter
- For example, "SHA1 usage TLSServer TLSClient" would disallow SHA1 certificates for TLSServer and TLSClient operations, but SignedJars would be allowed
- All of these constraints can be combined to constrain an algorithm when delimited by '&'. For example, to disable SHA1 certificate chains that terminate at marked trust anchors only for TLSServer operations, the constraint would be "SHA1 jdkCA & usage TLSServer"
- jdk.jar.disabledAlgorithms: One additional constraint was added to this .jar property to restrict JAR manifest algorithms
- "denyAfter" checks algorithm constraints on manifest digest algorithms inside a signed JAR file. The date given in the constraint is compared against the TSA timestamp on the signed JAR file. If there is no timestamp or the timestamp is on or after the specified date, the signed JAR file is treated as unsigned. If the timestamp is before the specified date, the .jar will operate as a signed JAR file. The syntax for restricting SHA1 in JAR files signed after January 1st 2018 is: "SHA1 denyAfter 2018-01-01". The syntax is the same as that for the certpath property, however certificate checking will not be performed by this property
CHANGES:
core-svc/java.lang.management. JMX Diagnostic improvements:
- com.sun.management.HotSpotDiagnostic::dumpHeap API is modified to throw IllegalArgumentException if the supplied file name does not end with “.hprof” suffix. Existing applications which do not provide a file name ending with the “.hprof” extension will fail with IllegalArgumentException. In that case, applications can either choose to handle the exception or restore old behavior by setting system property 'jdk.management.heapdump.allowAnyFileSuffix' to true.
security-libs/javax.net.ssl. Custom HostnameVerifier enables SNI extension:
- Earlier releases of JDK 8 Updates didn't always send the Server Name Indication (SNI) extension in the TLS ClientHello phase if a custom hostname verifier was used. This verifier is set via the setHostnameVerifier(HostnameVerifier v) method in HttpsURLConnection. The fix ensures the Server Name is now sent in the ClientHello body.
xml/jax-ws. Tighter secure checks on processing WSDL files by wsimport tool:
The wsimport tool has been changed to disallow DTDs in Web Service descriptions, specifically:
- DOCTYPE declaration is disallowed in documents
- External general entities are not included by default
- External parameter entities are not included by default
- External DTDs are completely ignored
To restore the previous behavior:
- Set the System property com.sun.xml.internal.ws.disableXmlSecurity to true
- Use the wsimport tool command line option –disableXmlSecurity
- NOTE: JDK 7 and JDK 6 support for this option in wsimport will be provided via a Patch release post July CPU
BUG FIXES:
- JFileChooser with Windows look and feel crashes on win 10
- Race Condition in java.lang.reflect.WeakCache
- java.nio.Bits.unaligned() doesn't return true on ppc
- After updating to Java8u131, the bind to rmiregistry is rejected by registryFilter even though registryFilter is set
- sun.management.LazyCompositeData.isTypeMatched() fail for composite types with items of ArrayType
- SafePointNode::_replaced_nodes breaks with irreducible loops
- NPE when JavaFX loads default stylesheet or font families if CCL is null
- WebEngine.getDocument().getDocumentURI() no longer returns null for loading a String of HTML
- Failed to load RSA private key from pkcs12
- Improved algorithm constraints checking
- Custom HostnameVerifier disables SNI extension