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http断点续传简单实现(java)

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/* 3,-[lG@o  
**SiteFileFetch.java #mkf2Z=t-  
*/ MUSsanCA  
package NetFox; Q89fXi0Ivb  
import java.io.*; Z)md]Twt  
import java.net.*; < n/ 2  
}$i/4?dYsQ  
9}5o> iR  
public class SiteFileFetch extends Thread { ~*x 2IPi H  
1!NrndJI  
*/2nh%>$  
SiteInfoBean siteInfoBean = null; //文件信息Bean ~G 3txd  
long[] nStartPos; //开始位置 9BAvE\o0  
long[] nEndPos; //结束位置 o59b#9  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 KwU;+=_.  
long nFileLength; //文件长度 SEVB.;  
boolean bFirst = true; //是否第一次取文件 \440gH`  
boolean bStop = false; //停止标志 h"nhDART<  
File tmpFile; //文件下载的临时信息 K&eT*JW>  
DataOutputStream output; //输出到文件的输出流 aYn5AP'PH  
U7Oa 13Qz  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 2T(7V[C%9  
public SiteFileFetch(SiteInfoBean bean) throws IOException 4:5M,p  
{ )qe rA  
siteInfoBean = bean; xpc{#/Nk  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); yD#(Iw  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Cz &3=),G  
if(tmpFile.exists ()) :$0yp`k  
{ t YxN^VqU  
bFirst = false; O_]hbXV0  
read_nPos(); B<i(Y1n[  
} zK&1ti@wln  
else ,3N>`]Km'  
{ d0-4KN2  
nStartPos = new long[bean.getNSplitter()]; *2pf> UzL  
nEndPos = new long[bean.getNSplitter()]; CK1A$$gnz  
} uehu\umt=  
5RAhm0Op~.  
^`k;~4'd  
bi^P k,'  
} Vl;zd=  
fvk(eWB  
7Mk>`4D'c  
public void run() #ID fJ2  
{ *jvP4Nz)k  
//获得文件长度 | 1zfXG,R  
//分割文件 ]6M,s0  
//实例FileSplitterFetch @yo6w}3+-  
//启动FileSplitterFetch线程 @<`V q  
//等待子线程返回 Lq;T\m_de  
try{ JOJuGB-d  
if(bFirst) fp*6Dv_  
{ *ow`}Q  
nFileLength = getFileSize(); n}t 9Nf_  
if(nFileLength == -1) .]s? 01Z  
{ b $yIM  
System.err.println("File Length is not known!"); -DK6(<:0  
} * V7mM?  
else if(nFileLength == -2) Yxbg _RQm  
{ T*%rhnTv0  
System.err.println("File is not access!"); O-[  
} "{\xBX~oM  
else J e,o(:  
{ +80bG(I_  
for(int i=0;i<nStartPos.length;i++) P;o  {t  
{ JsNj!aeU%  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); qS9<_if2  
} D'vaK89\  
for(int i=0;i<nEndPos.length-1;i++) 7B=VH r  
{ :;eQ*{ `\  
nEndPos = nStartPos[i+1]; WMC\J(@.  
} T0Xm}i  
nEndPos[nEndPos.length-1] = nFileLength; ;i\N!T{>  
} ^2);*X>  
} GcDA0%i  
L9N }lH  
n}_}#(a  
//启动子线程 Rk7F;2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .{\eco  
for(int i=0;i<nStartPos.length;i++) qdn_ ZE  
{ xT]t3'y|-  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lg8@^Pm$r;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /]^Y\U^  
nStartPos,nEndPos,i); ^C1LQ Z  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ge(,>xB  
fileSplitterFetch.start(); 1G7l+6w5~^  
} Kei0>hBi  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sOlnc6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &l3(+4Sh  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?_d6 ;  
nEndPos = " + nFileLength); w;yzgj:n&f  
// fileSplitterFetch[nPos.length-1].start(); R~T}  
_dRB=bl"O  
vi *A 5  
//等待子线程结束 G{]RC^Zo  
//int count = 0; Jx~H4y=z  
//是否结束while循环 jLM([t  
boolean breakWhile = false; l)*(UZ"  
|Q%P4S"B?  
V:'F_/&X?  
while(!bStop) ZnRT$ l O  
{ *Z^`H!&  
write_nPos(); A&)2m  
Utility.sleep(500); }oA>0Nw$K  
breakWhile = true; )WbWp4  
C1e@{>  
]95VM yN  
for(int i=0;i<nStartPos.length;i++) tE_n>~Zs  
{ ; cvMNU$fN  
if(!fileSplitterFetch.bDownOver) | bRU=dg  
{ [K$5 Rm5  
breakWhile = false;  $8rnf  
break; IHdA2d?.]  
} ,|s*g'u  
} A5J41yH  
if(breakWhile) v}N\z2A  
break; r'jUB^E  
&>C+5`bg  
"WuUMt  
//count++; cI'n[G  
//if(count>4) xi(1H1KN5B  
// siteStop(); 'fl< ac,.  
} 9D+k71"+  
$] "M`h  
 ?bVIH?  
System.err.println("文件下载结束!"); n|)((W  
} %K4M`R|2]  
catch(Exception e){e.printStackTrace ();} R|$AcNp  
} p|.5;)%|  
m9A%Z bQ^  
5RN!"YLI3  
//获得文件长度 mf$YsvPq*+  
public long getFileSize() Mq)]2>"v  
{ (87| :{  
int nFileLength = -1; RW+u5Y  
try{ I51]+gEN  
URL url = new URL(siteInfoBean.getSSiteURL()); :Q>e54]'&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p$9Aadi]  
httpConnection.setRequestProperty("User-Agent","NetFox"); / Qd` ?  
U,#x\[3!Jt  
eZAMV/]jH  
int responseCode=httpConnection.getResponseCode(); '0+~]4&}q  
if(responseCode>=400) pQBn8H|Y  
{ tngB;9c+w  
processErrorCode(responseCode); n}.e(z_"  
return -2; //-2 represent access is error Hs'~) T  
} gAWi&  
XJ\R'?j  
DOJydYds  
String sHeader; 9>w~B|/  
Bh2l3J4X  
<[)-Q~Gg5  
for(int i=1;;i++) W&Fm ;m@M  
{ 9GH5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a%B&F|u  
//Utility.log(in.readLine()); '~&W'='b;  
sHeader=httpConnection.getHeaderFieldKey(i); wpM2{NTP  
if(sHeader!=null) 6wh PW .  
{ ?iP7Ki  
if(sHeader.equals("Content-Length")) Pgr2 S I  
{ (T#$0RFq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qisvGHo  
break; AJ7^'p9Y  
} xyL)'C  
} B#S8j18M  
else h'-4nu;*  
break; 8C@u+tx  
} * ) <+u~  
} >|A,rE^Ojt  
catch(IOException e){e.printStackTrace ();} S[3"?$3S  
catch(Exception e){e.printStackTrace ();} W:]2T p  
e9{0hw7  
t<Yi!6  
Utility.log(nFileLength); "jum*<QZz  
PiKP.  
x^[,0?y2  
return nFileLength; 6]b"n'G  
} Gy/w #4xj  
uKP4ur@1  
" _2 k 3  
//保存下载信息(文件指针位置) T<pG$4_  
private void write_nPos() w-pgtO|Us  
{ ce\d35x!  
try{ !6'N-b1  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Dhn7N8(LF!  
output.writeInt(nStartPos.length); 4-.K<-T%D  
for(int i=0;i<nStartPos.length;i++) b!@PS$BTxq  
{ }4YzP 4  
// output.writeLong(nPos); HXa[0VOx  
output.writeLong(fileSplitterFetch.nStartPos); .g*N +T6O  
output.writeLong(fileSplitterFetch.nEndPos); X>[i<ei  
} B>L7UQ6_[  
output.close(); gUru=p  
} {1OxJn1hd  
catch(IOException e){e.printStackTrace ();} $o?U=  
catch(Exception e){e.printStackTrace ();} Dm}eX:'{  
} ^<OYW|q?\r  
gQ{ #C'  
rpR yB9  
//读取保存的下载信息(文件指针位置) JLE&nbKS  
private void read_nPos() =Nt HV4=b  
{ sr6 BC.  
try{ ;n Bf  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Wn=sF,c  
int nCount = input.readInt(); &" t~d}Rg  
nStartPos = new long[nCount]; w. k9{f  
nEndPos = new long[nCount]; L5FOlzn  
for(int i=0;i<nStartPos.length;i++) [_'A(.  
{ 6#+&/ "*  
nStartPos = input.readLong(); 9Y,JYc#  
nEndPos = input.readLong(); ~JXz  
} 2xLtJR4L  
input.close(); cb9-~*1  
} ?.VKVTX^  
catch(IOException e){e.printStackTrace ();} _cs(f<>oCO  
catch(Exception e){e.printStackTrace ();} T o["o!(;z  
} M(I%y0  
X vaIOt>A  
$v@$C4  
private void processErrorCode(int nErrorCode) juOStTq<  
{ R!j#  
System.err.println("Error Code : " + nErrorCode); OZxJDg  
} >)ekb7  
q~R8<G%YK  
[;z\bV<S  
//停止文件下载 *<xu3){:c  
public void siteStop() Qfm$q~`D^W  
{ "@nH;Xlq  
bStop = true; 4?+K `  
for(int i=0;i<nStartPos.length;i++) -"I$$C  
fileSplitterFetch.splitterStop(); j hm3:;Z  
c#N4XsG,  
lr>NG,N  
} @Ul3J )=m  
} MQ!4"E5"j  
//负责部分文件的抓取 epiviCYC  
**FileSplitterFetch.java B"&-) (  
*/ :8)Jnh\5  
package NetFox; 'v]0;~\mp>  
#BLHHK/[  
AZ3T#f![L@  
import java.io.*; .|O T#"LP  
import java.net.*; /qIQE&V-  
|_TiF ;^  
))=6g@(  
public class FileSplitterFetch extends Thread { eC!=4_lx)  
oK\zyNK  
hU$o^ICH  
String sURL; //File URL 0zH-g  
long nStartPos; //File Snippet Start Position R2Tt6  
long nEndPos; //File Snippet End Position -MTk9<qnT  
int nThreadID; //Thread's ID F$a s#.7FF  
boolean bDownOver = false; //Downing is over X hq ss),  
boolean bStop = false; //Stop identical H@uu;:l<7A  
FileAccessI fileAccessI = null; //File Access interface w6V/Xp][U  
;|Mfq` s  
C1D:Xi-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y47N(;vy  
{ \V$qAfP)  
this.sURL = sURL; _Xd"'cXw  
this.nStartPos = nStart; \}jA1oy  
this.nEndPos = nEnd; A]|w1nq  
nThreadID = id; O-V|=t  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a}%f +`z  
} sq2:yt  
K KB+o)*W  
BXYHJ  
public void run() sQ}|Lu9hZ  
{ vu+g65"  
while(nStartPos < nEndPos && !bStop) hBX*02p   
{ M3jUnp&  
Ur])*#  
,4Q4{Tx  
try{ ZHNL ~=r}  
URL url = new URL(sURL); |P>7C  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); , MXU]{  
httpConnection.setRequestProperty("User-Agent","NetFox"); T<B}Z11R  
String sProperty = "bytes="+nStartPos+"-"; 4QA~@pBX^{  
httpConnection.setRequestProperty("RANGE",sProperty); !_ W/p`Tc  
Utility.log(sProperty); s/7Z.\  
=%m{|HQ`  
J#$U<`j*G  
InputStream input = httpConnection.getInputStream(); @[g7\d  
//logResponseHead(httpConnection); 3jAr"xc  
O t)}:oG  
X84T F~2Y  
byte[] b = new byte[1024]; i O$87!  
int nRead; ~M}{rl.n=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }b\hRy~=r  
{ "-=fi 'D  
nStartPos += fileAccessI.write(b,0,nRead); =Dq&lm,n  
//if(nThreadID == 1) ^m#tWb)f  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T [SK>z  
} )$!b`u  
*S}@DoXS  
 T01Iu  
Utility.log("Thread " + nThreadID + " is over!"); OIPY,cj~  
bDownOver = true; x-[ItJ% l  
//nPos = fileAccessI.write (b,0,nRead); hS,&Nj+  
} 1 sHjM %  
catch(Exception e){e.printStackTrace ();} hoq2zDjD  
} c& ;@i$X(  
} D6L+mTN  
aZb\uMePK  
;eYG\uKC{  
//打印回应的头信息 HEVj K$  
public void logResponseHead(HttpURLConnection con) "Wj{+ |f  
{ w^0hVrws=,  
for(int i=1;;i++) u+j\PWOtm  
{ "9_$7.q<y  
String header=con.getHeaderFieldKey(i); 3:iEt (iCI  
if(header!=null) S"&Gutu3o  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >`AK'K8{M  
Utility.log(header+" : "+con.getHeaderField(header)); ~2Wus8X-  
else  )kWxp  
break; p3A9 <g  
} LFax$CZc  
} 3Z?ornS  
5mZ2CDV  
TLsF c^X  
public void splitterStop() {5Bj*m5  
{ q}t]lD %C  
bStop = true; bo|THS  
} LTe ({6l0  
gF,=rT1:>r  
}i8y/CA  
} #^L&H oo6  
^s{Ff+]W  
0#WN2f, <:  
/* ?b+Y])SJK  
**FileAccess.java ~P'.R.e  
*//文件访问(定位,写) h^ Cm\V  
package NetFox; )g'J'_Sl  
import java.io.*; V*@aE  
5REFz  
UfX~GC;B  
public class FileAccessI implements Serializable{ zcP=+Y)YA  
Dz0D ^(;V  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _8.TPB]no  
RandomAccessFile oSavedFile; |#_p0yPy  
long nPos; w x]?D%l  
Onq^|r's&  
`PbY(6CF  
public FileAccessI() throws IOException Z+v,o1  
{ `^[k8Z(  
this("",0); A;L ]=J  
} N~,Ipf  
0I.KHIB k  
%j\&}>P4$  
public FileAccessI(String sName,long nPos) throws IOException ui>jJ(  
{ Kzrd<h]`)  
oSavedFile = new RandomAccessFile(sName,"rw"); uP* kvi:e  
this.nPos = nPos; &b|RoPV  
oSavedFile.seek(nPos); vQ}ZfP  
} x#`p.sfVo  
Z9DfwWI2nu  
N)"8CvQL  
public synchronized int write(byte[] b,int nStart,int nLen) [_JdV(]$  
{ vi}16V84l  
int n = -1; *<sc[..)  
try{ ~pZ0B#K J  
oSavedFile.write(b,nStart,nLen); &{? M} 2I  
n = nLen; sbmtx/%U  
} kU/MvoV  
catch(IOException e) WJD2(el  
{ jQ V[zcM  
e.printStackTrace (); p9)YRLOh.  
} Q/SO%E`E  
'd~(=6J  
qGA|.I9,  
return n; e8<}{N0,n  
} S a +Y/  
+#eol~j9N  
sMMOZ'bT  
} Aars\   
{rcN_N%  
s;I @En  
/* "<=4]Z  
**SiteInfoBean.java 59zWB,y(P  
*/ a=}1`Q  
package NetFox; /ugWl99.W  
8|zavH#P  
n$C- ^3 c  
public class SiteInfoBean { GKFRZWXdT  
7K.75%}  
nms[No?  
private String sSiteURL; //Site's URL nod&^%O"  
private String sFilePath; //Saved File's Path rci,&>L"  
private String sFileName; //Saved File's Name +%XByY5  
private int nSplitter; //Count of Splited Downloading File 1Rd|P<y  
-rU_bnm  
\OVFZ D  
public SiteInfoBean() Z5'^81m$o  
{//nSplitter的缺省值为5 ~ L4NK#  
//default value of nSplitter is 5 yz K<yvN  
this("","","",5); %Lh%bqGz  
}  ijOp{  
, ~ 1+MZ=  
O5r8Ghf )  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q%x i>H.:{  
{ 4m< ]qw  
sSiteURL= sURL;  skl3/!  
sFilePath = sPath; vSHPN|*  
sFileName = sName; d3q%[[@  
this.nSplitter = nSpiltter; xmnBG4,f  
<<01@Q <  
znE1t%V  
} dXxf{|gk>  
5@5 *}[M  
_5rKuL  
public String getSSiteURL() c~tl0XU1  
{ ZRf9'UwS  
return sSiteURL; u~OlJ1V  
} T!,5dt8L  
Bg),Q8\I  
^mq(j_E.  
public void setSSiteURL(String value) =W7-;&  
{ gfK_g)'2U  
sSiteURL = value; +\Vw:~e  
} h"ZIh= j@  
`R2Iw I&  
>s5}pkAv|e  
public String getSFilePath() =J1V?x=l@  
{ p K-tj  
return sFilePath; z@VL?A(3  
} x[lIib1s  
_6fy'%J=U  
?w(hPUd!2  
public void setSFilePath(String value) `n>|rd  
{ \'Ca1[y@B  
sFilePath = value; sAc1t`  
} lPR^~&/  
KS8@A/f  
i@+m<YS:2>  
public String getSFileName() )tBz=hy#  
{ =u}~\ 'd  
return sFileName; +A8q.-N G  
} .T7CMkYt  
9xbT?$^  
xy:Mb =r  
public void setSFileName(String value) FQ 0&{ulb  
{ A4,%l\di<  
sFileName = value; BlpyE[h T  
} JE}VRMNr  
5, ,'hAq_  
5[)5K?%  
public int getNSplitter() bK6^<,~  
{ 6MM\nIU)/  
return nSplitter; vk E]$4P[$  
} i&H^xgm  
j-BNHX  
 jfK&CA  
public void setNSplitter(int nCount) ifS#9N|8  
{ %JDQ[%3qY  
nSplitter = nCount; ynw(wSH=  
} =)Hu(;Yv  
} nam]eW  
w>*Jgc@A*  
YT?Lt!cl=  
/* m4~ |z  
**Utility.java '1DY5`i{  
*/ Ml c_w19C9  
package NetFox; HTQTDbhV^  
FiMM-c|  
k}:;`ST  
public class Utility { :=*G7ZyW$  
}< '6FxR  
*@bz<{!  
public Utility() H<!q@E ;  
{ gOnZ#  
v76P?[  
gw"SKp!]  
} w-JWMgY8w  
[5' HlHK  
//线程睡眠 Ba?1q%eG  
public static void sleep(int nSecond) ! $mY.uu  
{ gpyio1V>  
try{ !2Ompcr1  
Thread.sleep(nSecond); 6IRRRtO(  
} =c \(]xX  
catch(Exception e) 1c QF(j_  
{ I(7 GVYM  
e.printStackTrace (); 4G:~|N.{p  
} 6h5g!GQD  
} P7W|e~]Yq  
@_"cMU!  
//日志 ? ch?q~e)  
public static void log(String sMsg) ,{G\-(\  
{ <gi~:%T  
System.err.println(sMsg); , poc!n//  
} |BM#rfQ  
4A"nm6  
p4IyKry,  
public static void log(int sMsg) ?J + jv  
{ z59;Qk  
System.err.println(sMsg); h0m5o V  
} |WS@q'  
} j~Fd8]@  
0kCo0{+n  
@ NDcO,]  
/* b]?5r)GK  
**TestMethod.java e8f 7*S8  
*/ &Y@),S9  
package NetFox; 075IW"p'  
+}at#%1@  
Z] r9lC  
public class TestMethod { * G*VY#L  
p @q20>^u  
o=94H7@  
public TestMethod() c}$>UhLe  
{ ///xx/weblogic60b2_win.exe 2HVqJib4Yn  
try{ 03)irq%l;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rD$5]%Y  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zs}h>$E5_B  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2{WZ?H93a  
fileFetch.start(); vv)w@A:Vn)  
} y|B HSc3  
catch(Exception e){e.printStackTrace ();} uPcx6X3]  
p q?# X0  
i@6g9\x+  
} |FT.x9e-  
m;"[b (u  
`K0.6i [p  
public static void main(String[] args) U) xeta+  
{ %!-t7K^mFq  
new TestMethod(); k>MXOUaW.  
} jqvw<+#  
} L-U4 8 i  
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