How to add Digital Signature in Java?
Digital signatures have become a cornerstone of secure, paperless workflows—especially in enterprise-grade Java applications. Whether you’re building financial systems, HR tools, or legal platforms, integrating digital signatures ensures document authenticity, integrity, and compliance with standards like DSC.
In this blog, we’ll walk you through how to add digital signature in Java, covering both the conceptual understanding and practical implementation. From signing PDFs to integrating with a signature API like KAiZEN, this guide is tailored for developers looking to streamline and secure their document processes with Java.
How to integrate eSignature into Java Applications:
Step 1:
Define Your Signers and Signing Order
Let’s define the below two users which the order of signing.
Signer Information
| Signer Name | Order | Signer Email |
|---|---|---|
| Signer 1 | 1 | signer1@gmail.com |
| Signer 2 | 2 | signer2@gmail.com |
-
Step 2:
Make an HTTP Call to KAiZEN’s API
Need to make a secure HTTP Callout to call the KAiZEN “Initiate Sign API” request as per the below details:
HTTP Request Parameters
Parameters Name Value Content-Type application/json Method POST Endpoint https://fa-kaizen-prod.azurewebsites.net/api/Sign/RequestStr?code=RTa1A0GW5Yl92OF54-73lRqglLFCt_0pVcg86hWf1EjtAzFuNROcdA== Body JSON Body with parameters Important Request Body Parameters
Parameters Name Description Required docContent Base64 Content for the PDF File Yes docName Name of the File Yes appToken Unique Code to initiate the request Yes requesterEmail Email address of the person initiating the request Yes requesterName Name of the person initiating the request Yes description Describes the document NO signers An array of the signers who needs to sign the document in the pre-defined order. Yes CallBackURL CallbackURL defines the url on which the KAiZEN should send a response once all the signers signs the document. It can be webservice url of Salesforce or any external page.
Eg: https://duumy.my.salesforce- sites.com/services/apexrest/KaizenCallbackURL/No newRequestEmailSubject Describes the email subject No requesterMessage Describes the prompt eSignature field No docDescription Describes the document No -
Step 3:
Java Code Sample for Integration
OkHttpClient client = new OkHttpClient().newBuilder() .build(); MediaType mediaType = MediaType.parse("application/json"); RequestBody body = RequestBody.create(mediaType, "{\n \"docContent\":\"<>\",\n \"requesterEmail\": \"xyz@gmail.com\",\n \"requesterName\": \"XYZ\",\n \"requesterPhone\": \"xxxxx-xxx-xxxx\",\n \"description\" :\"\",\n \"newRequestEmailSubject\":\"You have a document to sign\",\n \"requesterMessage\": \"Kindly eSign your KAiZEN Test PDF\",\n \"signers\": [\n {\n \"signerEmail\": \"signer1@gmail.com\",\n \"signerName\": \"Signer1\",\n \"signerPhone\": \"xx-xxx-xxxx-xxx\",\n \"order\": \"1\",\n \"signerRole\": \"signer\"\n \n },{\n \"signerEmail\": \"signer2@gmail.com\",\n \"signerName\": \"Signer2\",\n \"signerPhone\": \"xxx-xxx-xxxx-xxxx\",\n \"order\": \"2\",\n \"signerRole\": \"reviewer\"\n \n }\n ],\n \n \"docDescription\": \"Base 64 string based test doc\",\n \"callbackurl\": \"\"\n}"); Request request = new Request.Builder() .url("https://fa-kaizen-staging.azurewebsites.net/api/Sign/RequestStr?code=mLgEBTpi9dfooQ6TB9gc7sa4qiIuuxmqQYoTx8nQQ1StAzFu93g06A==") .method("POST", body) .addHeader("Content-Type", "application/json") .build(); Response response = client.newCall(request).execute(); Sample HTTP Response:
{ “FailRules”: [], “Data”: { “SignRequestId”: “01HV6MEARQD3X8ZXXX5FR3YDB8”, “RequestNo”: “KAiZEN-118” } }Once the request is submitted, it will send a response with the request Id. If the callback url is configured, it will send a signed copy of the document on the defined url, once all the signers will sign and review the document.
Once the request is sent out to the signers, each signer will receive an email to sign the document in the order as defined in the request.
How KAiZEN eSign Works
-
Check Your Inbox
The signer will receive an email from KAiZEN with a prompt to sign the document.
-
Click to Start Signing
Inside the email, click the “Sign here” button. This opens the document in the secure KAiZEN signing editor.
-
Sign the Document
After clicking on the “Sign Here” button. You’ll get a popup where you can choose the following methods to eSign:
- Initials
- Draw your signature
- Upload an image of your signature
- Recently Used Signs
-
Submit and Done
Once you’ve placed your signature, click Submit. The next signer in the sequence will then be notified.
-
After All Signers Complete
Once every signer has completed the process:
- Each signer will receive an email with the final signed document.
- If a callback URL was configured, a copy of the signed document will be automatically sent to that system (e.g., Java or your application).
Conclusion
Integrating digital signatures into your Java application boosts security, ensures compliance, and streamlines document workflows. With tools like KAiZEN, it’s easier than ever to implement reliable and scalable eSigning features directly into your Java stack.
How to add Digital Signature in Java?
Digital signatures have become a cornerstone of secure, paperless workflows—especially in enterprise-grade Java applications. Whether you’re building financial systems, HR tools, or legal platforms, integrating digital signatures ensures document authenticity, integrity, and compliance with standards like DSC.
In this blog, we’ll walk you through how to add digital signature in Java, covering both the conceptual understanding and practical implementation. From signing PDFs to integrating with a signature API like KAiZEN, this guide is tailored for developers looking to streamline and secure their document processes with Java.
How to integrate eSignature into Java Applications:
Step 1:
Define Your Signers and Signing Order
Let’s define the below two users which the order of signing.
Signer Information
| Signer Name | Order | Signer Email |
|---|---|---|
| Signer 1 | 1 | signer1@gmail.com |
| Signer 2 | 2 | signer2@gmail.com |
-
Step 2:
Make an HTTP Call to KAiZEN’s API
Need to make a secure HTTP Callout to call the KAiZEN “Initiate Sign API” request as per the below details:
HTTP Request Parameters
Parameters Name Value Content-Type application/json Method POST Endpoint https://fa-kaizen-prod.azurewebsites.net/api/Sign/RequestStr?code=RTa1A0GW5Yl92OF54-73lRqglLFCt_0pVcg86hWf1EjtAzFuNROcdA== Body JSON Body with parameters Important Request Body Parameters
Parameters Name Description Required docContent Base64 Content for the PDF File Yes docName Name of the File Yes appToken Unique Code to initiate the request Yes requesterEmail Email address of the person initiating the request Yes requesterName Name of the person initiating the request Yes description Describes the document NO signers An array of the signers who needs to sign the document in the pre-defined order. Yes CallBackURL CallbackURL defines the url on which the KAiZEN should send a response once all the signers signs the document. It can be webservice url of Salesforce or any external page.
Eg: https://duumy.my.salesforce- sites.com/services/apexrest/KaizenCallbackURL/No newRequestEmailSubject Describes the email subject No requesterMessage Describes the prompt eSignature field No docDescription Describes the document No -
Step 3:
Java Code Sample for Integration
OkHttpClient client = new OkHttpClient().newBuilder() .build(); MediaType mediaType = MediaType.parse("application/json"); RequestBody body = RequestBody.create(mediaType, "{\n \"docContent\":\"<>\",\n \"requesterEmail\": \"xyz@gmail.com\",\n \"requesterName\": \"XYZ\",\n \"requesterPhone\": \"xxxxx-xxx-xxxx\",\n \"description\" :\"\",\n \"newRequestEmailSubject\":\"You have a document to sign\",\n \"requesterMessage\": \"Kindly eSign your KAiZEN Test PDF\",\n \"signers\": [\n {\n \"signerEmail\": \"signer1@gmail.com\",\n \"signerName\": \"Signer1\",\n \"signerPhone\": \"xx-xxx-xxxx-xxx\",\n \"order\": \"1\",\n \"signerRole\": \"signer\"\n \n },{\n \"signerEmail\": \"signer2@gmail.com\",\n \"signerName\": \"Signer2\",\n \"signerPhone\": \"xxx-xxx-xxxx-xxxx\",\n \"order\": \"2\",\n \"signerRole\": \"reviewer\"\n \n }\n ],\n \n \"docDescription\": \"Base 64 string based test doc\",\n \"callbackurl\": \"\"\n}"); Request request = new Request.Builder() .url("https://fa-kaizen-staging.azurewebsites.net/api/Sign/RequestStr?code=mLgEBTpi9dfooQ6TB9gc7sa4qiIuuxmqQYoTx8nQQ1StAzFu93g06A==") .method("POST", body) .addHeader("Content-Type", "application/json") .build(); Response response = client.newCall(request).execute(); Sample HTTP Response:
{ “FailRules”: [], “Data”: { “SignRequestId”: “01HV6MEARQD3X8ZXXX5FR3YDB8”, “RequestNo”: “KAiZEN-118” } }Once the request is submitted, it will send a response with the request Id. If the callback url is configured, it will send a signed copy of the document on the defined url, once all the signers will sign and review the document.
Once the request is sent out to the signers, each signer will receive an email to sign the document in the order as defined in the request.
How KAiZEN eSign Works
-
Check Your Inbox
The signer will receive an email from KAiZEN with a prompt to sign the document.
-
Click to Start Signing
Inside the email, click the “Sign here” button. This opens the document in the secure KAiZEN signing editor.
-
Sign the Document
After clicking on the “Sign Here” button. You’ll get a popup where you can choose the following methods to eSign:
- Initials
- Draw your signature
- Upload an image of your signature
- Recently Used Signs
-
Submit and Done
Once you’ve placed your signature, click Submit. The next signer in the sequence will then be notified.
-
After All Signers Complete
Once every signer has completed the process:
- Each signer will receive an email with the final signed document.
- If a callback URL was configured, a copy of the signed document will be automatically sent to that system (e.g., Java or your application).
Conclusion
Integrating digital signatures into your Java application boosts security, ensures compliance, and streamlines document workflows. With tools like KAiZEN, it’s easier than ever to implement reliable and scalable eSigning features directly into your Java stack.
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