public void deleteDocument(){
    system.debug('VISUALFORCEPARAMS' +documentType + documentCateogry + documentId);
    hardDeleteDocument(account.Business__c, account.Customer_Number__c, documentCateogry, documentType, documentId);
}

<apex:tabPanel >
    <apex:tab label="Search Documents" id="searchDoc">
        <apex:form >
            <apex:pageMessages />
            <apex:inputTextarea styleClass="debugArea" label="Access Token" disabled="true" value="{!access_token}"></apex:inputTextarea>
            <br/>
            <apex:inputTextarea styleClass="debugArea" label="Request" disabled="true" value="{!request}"></apex:inputTextarea>
            <br/>
            <apex:inputTextarea styleClass="debugArea" label="Response" disabled="true" value="{!response}"></apex:inputTextarea>
            <br/>
            <apex:commandButton action="{!searchRecords}" value="Search"></apex:commandButton>
            <apex:pageBlock >
                <apex:pageBlockTable value="{!foundDocuments}" var="doc">
                    <apex:column headerValue="action">
                        <apex:commandButton value="View">
                        </apex:commandButton>
                        <apex:commandButton value="Download">
                        </apex:commandButton>
                        <apex:commandButton value="Delete" action="{!deleteDocument}" >
                            <apex:param value="{!doc.category}" name="docCategory" assignTo="{!documentCateogry}"></apex:param>
                            <apex:param value="{!doc.type}" name="docType" assignTo="{!documentType}"></apex:param>
                            <apex:param value="{!doc.fileId}" name="fileId" assignTo="{!documentId}"></apex:param>
                        </apex:commandButton>
                    </apex:column>
                    <apex:column headerValue="ownerIdentifier" value="{!doc.ownerIdentifier}"></apex:column>
                    <apex:column headerValue="ownerType" value="{!doc.ownerType}"></apex:column>
                    <apex:column headerValue="businessUnit" value="{!doc.businessUnit}"></apex:column>
                    <apex:column headerValue="documentFileName" value="{!doc.documentFileName}"></apex:column>
                    <apex:column headerValue="fileId" value="{!doc.fileId}"></apex:column>
                    <apex:column headerValue="format" value="{!doc.format}"></apex:column>
                    <apex:column headerValue="type" value="{!doc.type}"></apex:column>
                    <apex:column headerValue="category" value="{!doc.category}"></apex:column>
                    <apex:column headerValue="size" value="{!doc.size}"></apex:column>
                    <apex:column headerValue="lastModified" value="{!doc.lastModified}"></apex:column>
                    <apex:column headerValue="originalTimestamp" value="{!doc.originalTimestamp}"></apex:column>
                    <apex:column headerValue="uploadDate" value="{!doc.uploadDate}"></apex:column>
                    <apex:column headerValue="uploaderType" value="{!doc.uploaderType}"></apex:column>
                    <apex:column headerValue="uploaderIdentifier" value="{!doc.uploaderIdentifier}"></apex:column>
                    <apex:column headerValue="encrypted" value="{!doc.encrypted}"></apex:column>
                    <apex:column headerValue="comment" value="{!doc.comment}"></apex:column>
                    <apex:column headerValue="status" value="{!doc.status}"></apex:column>
                    <apex:column headerValue="referenceId" value="{!doc.referenceId}"></apex:column>
                </apex:pageBlockTable>
            </apex:pageBlock>
            </apex:form>
    </apex:tab>
    <apex:tab label="Upload Documents" id="uploadDoc">
        <apex:form >
            <apex:pageMessages />
            <br/>
            <apex:inputTextarea styleClass="debugArea" label="Access Token" disabled="true" value="{!access_token}"></apex:inputTextarea>
            <br/>
            <apex:inputTextarea styleClass="debugArea" label="Request" disabled="true" value="{!request}"></apex:inputTextarea>
            <br/>
            <apex:inputTextarea styleClass="debugArea" label="Response" disabled="true" value="{!response}"></apex:inputTextarea>
            <br/>
            <apex:inputfile value="{!file.body}" filename="{!file.name}"/>
            <br/>
            <br/>
            <apex:inputText label="fileType" html-placeholder="fileType" id="fileType" required="true" style="width:250px;" value="{!fileType}"></apex:inputText>
            <apex:commandbutton value="Upload" action="{!uploadDocument}"/>
        </apex:form>
    </apex:tab>
    <apex:tab label="Retrieve Document" id="retrieveDoc">
        <apex:form >
            <apex:pageMessages />
            <br/>
            <apex:inputTextarea styleClass="debugArea" label="Access Token" disabled="true" value="{!access_token}"></apex:inputTextarea>
            <br/>
            <apex:inputTextarea styleClass="debugArea" label="Request" disabled="true" value="{!request}"></apex:inputTextarea>
            <br/>
            <apex:inputTextarea styleClass="debugArea" label="Response" disabled="true" value="{!response}"></apex:inputTextarea>
            <br/>
            <br/>
            <apex:inputText label="fileId" html-placeholder="fieldId" id="fileId" required="true" style="width:250px;" value="{!searchFileId}"></apex:inputText>
            <br/>
            <br/>
            <apex:commandbutton value="Retrieve" action="{!retrieveContents}"/>
        </apex:form>
    </apex:tab>
</apex:tabPanel>