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http断点续传简单实现(java)

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/* PhLn8jNti  
**SiteFileFetch.java y4yhF8E>;U  
*/ UB@Rs|)  
package NetFox; )w em|:H  
import java.io.*; ~"gA,e-)  
import java.net.*; C-xr"]#]  
aNsBcov3O  
#x@$ lc=k3  
public class SiteFileFetch extends Thread { ]dVGUG8  
t}_r]E,{u  
XoK:N$\}t  
SiteInfoBean siteInfoBean = null; //文件信息Bean 8H[<X_/ke  
long[] nStartPos; //开始位置 TT%M' 5&  
long[] nEndPos; //结束位置 /*~EO{o  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 'B$yo]  
long nFileLength; //文件长度 J[&@PUy  
boolean bFirst = true; //是否第一次取文件 ?JbilK}a  
boolean bStop = false; //停止标志 je\Ph5"  
File tmpFile; //文件下载的临时信息 E#RDqL*J  
DataOutputStream output; //输出到文件的输出流  y`iBFC;_  
s3N'02G  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) z9f-.72"X  
public SiteFileFetch(SiteInfoBean bean) throws IOException ]2A^1Del  
{ Ng&%o  
siteInfoBean = bean; m[osg< CR_  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); cdH>n)  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 5PCqYN(:B  
if(tmpFile.exists ()) j8i[ONq^  
{ d7^}tM  
bFirst = false; iO{hA  
read_nPos(); 9yu\ Ot  
} ho{*Cjv  
else Oamg]ST  
{ &<g|gsG`  
nStartPos = new long[bean.getNSplitter()]; uh_RGM&  
nEndPos = new long[bean.getNSplitter()]; ,oe <  
} @&!ZZ 1V8  
y8Ir@qp5  
1.JK3 3  
_RYxD"m y  
} T.F!+  
~G p [_ %K  
3Aip}<1  
public void run() iozt&~o  
{ T"Y+m-<%  
//获得文件长度 umfD>" ^I  
//分割文件 1nM  #kJ"  
//实例FileSplitterFetch iXkF1r]i  
//启动FileSplitterFetch线程 ]#<4vl\  
//等待子线程返回 H'5)UX@LP  
try{ )}R0Y=e  
if(bFirst) KkyVSoD\  
{ 5ta `%R_  
nFileLength = getFileSize(); ,pfG  
if(nFileLength == -1) P8 c`fbkX2  
{ 9=M$AB  
System.err.println("File Length is not known!"); ZoqZap6e  
} XW H5d-  
else if(nFileLength == -2) 8%mu8l  
{ ,KZ~?3$yj  
System.err.println("File is not access!"); /HEw-M9z  
} N% B>M7-=  
else ]mq|w  
{ M?49TOQA  
for(int i=0;i<nStartPos.length;i++) G>=*yqo  
{ C& f= ywi0  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); FGJ1dBLr  
} xu%k~4cB,  
for(int i=0;i<nEndPos.length-1;i++) =*.~BG  
{ P;no?  
nEndPos = nStartPos[i+1]; B@))8.h]  
} gg/-k;@ Rf  
nEndPos[nEndPos.length-1] = nFileLength; ]0OR_'?,  
} J{<X 7uB  
} T<>,lQs(a  
Q\vpqE! 9  
!F-w3 ]  
//启动子线程 Kw^7>\  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I][*j  
for(int i=0;i<nStartPos.length;i++) H41?/U,{  
{ *>}@7}f  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S13nL^=i  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6|=f$a  
nStartPos,nEndPos,i); e%M;?0j  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wQf-sk#  
fileSplitterFetch.start(); {YC@T(  
} 3=[mP, pLh  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8Fh)eha9f  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >Tx?%nQ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,p a {qne  
nEndPos = " + nFileLength); t?gic9 q  
// fileSplitterFetch[nPos.length-1].start(); S hWJ72c  
0mVNQxHI  
gJ{)-\  
//等待子线程结束 ~?}Emn;t  
//int count = 0; kTB 0b*V  
//是否结束while循环 >U>(`r*  
boolean breakWhile = false; -2[a2^a'  
u=sp`%?  
 _[3D  
while(!bStop) "sCRdx]_  
{ eByz-,{P  
write_nPos(); JQI: sj  
Utility.sleep(500); `w Vyb>T  
breakWhile = true; 0d&6lqTo  
^CX6&d  
F>l] 9!P|m  
for(int i=0;i<nStartPos.length;i++) !pW0qX\1n  
{ _{KG 4+5\X  
if(!fileSplitterFetch.bDownOver) dn3y\  
{ 4$<JHo @.  
breakWhile = false; =T@1@w  
break; <'*LRd$1  
} Q%G8U#Tm  
} niyV8v  
if(breakWhile) D>q9 3;p  
break; X"Swi&4  
NLqzi%s  
T5h H  
//count++; T8g$uFo  
//if(count>4) %u'u kcL7  
// siteStop(); ?tbrbkx  
} 5j(k:a+!H  
8Z~EwY*  
vs4>T^8e  
System.err.println("文件下载结束!"); ux4POO3C|  
} L8B! u9%  
catch(Exception e){e.printStackTrace ();} 7. oM J  
} z} #JK? u  
?@86P|19  
ZECfR>`x  
//获得文件长度 fJg+Ryo  
public long getFileSize() PW0LG^xp`  
{ `c$V$/IT  
int nFileLength = -1; &D<yX~  
try{ F^:3?JA _  
URL url = new URL(siteInfoBean.getSSiteURL()); a7opCmL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); > (<f 0  
httpConnection.setRequestProperty("User-Agent","NetFox"); H5|;{q:j  
9 68Ez  
9(Xn>G'iT  
int responseCode=httpConnection.getResponseCode(); "tK=+f`NM  
if(responseCode>=400) !N^@4*  
{ ;uGv:$([g  
processErrorCode(responseCode); YmG("z  
return -2; //-2 represent access is error (ZlU^Gw#UB  
} 307I$*%W  
n$R)>n Y  
[-w%/D%@  
String sHeader; ueNS='+m  
53 h0UL  
ckn(`I  
for(int i=1;;i++) uxz^/Gk  
{ |7~<Is~ *  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6S #Cl>v  
//Utility.log(in.readLine()); <_+X 88  
sHeader=httpConnection.getHeaderFieldKey(i); *4 n)  
if(sHeader!=null) r JB}qYD  
{ 8P`"M#fI  
if(sHeader.equals("Content-Length")) :4|4=mkr  
{ k5)om;.w  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i XN1I  
break; [Rb+q=z#  
} k?}Zg*  
} =(^3}x  
else j<$2hiI/?&  
break; eS! /(#T  
} dRMx[7jVA  
} []T8k9g/-  
catch(IOException e){e.printStackTrace ();} AQ Ojit6p  
catch(Exception e){e.printStackTrace ();} 4p wH>1  
FI.\%x  
I^]nqK  
Utility.log(nFileLength); a'T;x`b8U,  
Xa&kIq}(g  
D_MmW  
return nFileLength; gG uO  
} EM_d8o)`B  
 !u hT  
$~kA B8z  
//保存下载信息(文件指针位置) HZOMlOZ  
private void write_nPos() *WZA9G#V5  
{ JGZBL{8  
try{ @6]JIJE  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `0svy}  
output.writeInt(nStartPos.length); [>9is=>o.  
for(int i=0;i<nStartPos.length;i++) jWgX_//!  
{ +|f@^-  
// output.writeLong(nPos); sos5Y}  
output.writeLong(fileSplitterFetch.nStartPos); dWW.Y*339  
output.writeLong(fileSplitterFetch.nEndPos); O&&~NXI\  
} ;@J}}h'y  
output.close(); 06jQE2z2R  
} bd`P0f?  
catch(IOException e){e.printStackTrace ();} H*6W q  
catch(Exception e){e.printStackTrace ();} d=^z`nt !R  
} /V By^L:  
a.Vuu)+Quw  
r<\u6jF  
//读取保存的下载信息(文件指针位置) 0`H# '/  
private void read_nPos() 0{mex4  
{ ( 5~h"s  
try{ {+Jv+J9  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @|!z9Y*  
int nCount = input.readInt(); Va8&Z  
nStartPos = new long[nCount]; !9x}  
nEndPos = new long[nCount]; h];I{crh  
for(int i=0;i<nStartPos.length;i++) wY}@'pzX  
{ LQ% `c  
nStartPos = input.readLong(); Mihg:  
nEndPos = input.readLong(); ,?3G;-  
} %)n=x ne  
input.close(); Pz^544\~ou  
} _B0L.eF  
catch(IOException e){e.printStackTrace ();} 45oR=At n  
catch(Exception e){e.printStackTrace ();} 0IpmRH/  
} 0$njMnB2l  
 _4f;<FL  
g .\[o@H  
private void processErrorCode(int nErrorCode) W>LR\]Ti@  
{ .^g p?  
System.err.println("Error Code : " + nErrorCode); @XVTU  
} r=4eP(w=  
e# bn#  
54/=G(F   
//停止文件下载 `{Ul!  
public void siteStop() qWw=8Bq  
{ *h|U,T7ew  
bStop = true; / j^  
for(int i=0;i<nStartPos.length;i++) qb4z T  
fileSplitterFetch.splitterStop(); o}!PQ#`M  
Xeaj xcop#  
`2snz1>!j  
} 8- i#8'/x  
} _g. {MTQ  
//负责部分文件的抓取 *2?@ |<(r  
**FileSplitterFetch.java g5yJfRLxp  
*/ ]{iQ21`a-  
package NetFox; v:U-6W_)|  
5m*,8]!-  
nR~(0G,H  
import java.io.*; hQ i2U  
import java.net.*; XRH!]!  
OY d !v`<  
1qch]1 ^G  
public class FileSplitterFetch extends Thread { c:0L+OF}xY  
xwr8`?]y  
/\Ef%@  
String sURL; //File URL q@qsp&0/  
long nStartPos; //File Snippet Start Position dscgj5b1~  
long nEndPos; //File Snippet End Position . ^u,.  
int nThreadID; //Thread's ID TO_e^A#  
boolean bDownOver = false; //Downing is over Ngwb Q7)  
boolean bStop = false; //Stop identical R@0R`Zs  
FileAccessI fileAccessI = null; //File Access interface R2;  
B6"0OIDY"  
`gJ(0#ac  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yr6V3],Tp  
{ Kgv T"s.  
this.sURL = sURL; 0erNc'e  
this.nStartPos = nStart; :+Z%; Dc  
this.nEndPos = nEnd; y2v^-q3  
nThreadID = id; TV:9bn?r)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :Al!1BJQ  
} dI2 V>vk  
=vPj%oLp'a  
CAe!7HiR  
public void run() GVz6-T~\>  
{ @7u0v  
while(nStartPos < nEndPos && !bStop) \GBuWY3B  
{ K'xV;r7Nt  
9$Y=orpWxr  
0%B/,/PxD  
try{ \^LFkp  
URL url = new URL(sURL); $:6!H:ty  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wq{hF<  
httpConnection.setRequestProperty("User-Agent","NetFox"); [KQi.u  
String sProperty = "bytes="+nStartPos+"-"; 8(De^H lO  
httpConnection.setRequestProperty("RANGE",sProperty); g7|@  
Utility.log(sProperty); ]iWRo'  
zqku e%^?-  
[ )F<V!  
InputStream input = httpConnection.getInputStream(); 7^Uv7< pw  
//logResponseHead(httpConnection); yu|>t4#GT  
N[hG8f  
m'U0'}Ld};  
byte[] b = new byte[1024]; WxDh;*am:  
int nRead; "MsIjSu  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hoP]9&<T  
{ W)/#0*7  
nStartPos += fileAccessI.write(b,0,nRead); =wJX 0A|  
//if(nThreadID == 1) ;a/E42eN;  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TC('H[ ]  
} y5r4&~04  
V#HuIgf-  
r%_djUd  
Utility.log("Thread " + nThreadID + " is over!"); gUlo]!$  
bDownOver = true; OI*H,Z "  
//nPos = fileAccessI.write (b,0,nRead); 1 zZlC#V  
} |)&%A%m  
catch(Exception e){e.printStackTrace ();} W^Yxny  
} F [M,]?   
} J,hCvm  
M:8R -c#![  
s7<AfaJPF  
//打印回应的头信息 HQ g^ h  
public void logResponseHead(HttpURLConnection con) sK{e*[I>W  
{ 4 5e~6",  
for(int i=1;;i++) LLo;\WGZ  
{ .>S!ji  
String header=con.getHeaderFieldKey(i); IPk4 ;,  
if(header!=null) $ `c:&  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sx%[=g+<2(  
Utility.log(header+" : "+con.getHeaderField(header)); w(/S?d  
else b-DvW4B  
break; UZMd~|  
}  \zkg  
} R5D1w+  
!Ee:o"jG{  
d~H`CrQE*  
public void splitterStop() L#J1b!D&<6  
{ +R&gqja  
bStop = true; -~1~I e2  
} *p U x8yB  
Oz95  
/7kC<  
} AKC`TA*E  
8=l%5r^cq  
wp_0+$?s  
/* u_enqC3  
**FileAccess.java QV!up^Zso  
*//文件访问(定位,写) CrLrw T  
package NetFox; GJrG~T  
import java.io.*; :> '+"M2r  
pP_LR ks}  
6Oq 7#3]  
public class FileAccessI implements Serializable{ #e"[^_C@!  
mt .sucT  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d0D] Q  
RandomAccessFile oSavedFile; p{_ " bB  
long nPos; s<Ziegmw|g  
eFgA 8kY)  
;u JMG  
public FileAccessI() throws IOException 9w"*y#_  
{ DQ3<$0  
this("",0); h{Y",7] !  
} LVGe]lD  
l#o ~W`  
S[gx{Bxiw  
public FileAccessI(String sName,long nPos) throws IOException qGo.WZ$  
{ 1zv'.uu.,  
oSavedFile = new RandomAccessFile(sName,"rw"); $FVNCFN%  
this.nPos = nPos; e6*8K@LHB  
oSavedFile.seek(nPos); kVgTGC"L=  
} fhiM U8(&  
{) XTk &"  
N8jIMb'<  
public synchronized int write(byte[] b,int nStart,int nLen) ';CNGv -  
{ )nkY_' BV  
int n = -1; y(#e}z:  
try{ D*jM1w_`  
oSavedFile.write(b,nStart,nLen); -@'FW*b  
n = nLen; @d'j zs  
} VA%J\T|G2\  
catch(IOException e) yWK)vju"  
{ 4hB]vY\T  
e.printStackTrace (); y29m/i:  
} kiEa<-]  
2y4bwi  
C|bET  
return n; 9up3[F$  
} Rcuz(yS8  
dtDFoETz  
81F9uM0  
} yi[x}ffdE  
F9^S"qv$  
LVy yO3e  
/* F59 TZI  
**SiteInfoBean.java }MySaL>  
*/ ?ub35NLa  
package NetFox; P55fL-vo|}  
Uo49*Mr  
h[ ZN+M  
public class SiteInfoBean { Wwo0%<2y  
+`4A$#$+y  
6]N.%Y[(  
private String sSiteURL; //Site's URL @Qe0! (_=  
private String sFilePath; //Saved File's Path rv;3~'V  
private String sFileName; //Saved File's Name BtZyn7a  
private int nSplitter; //Count of Splited Downloading File g(g& TO  
/v}`l  
 ]~-r} `]  
public SiteInfoBean() ZCw]m#lS  
{//nSplitter的缺省值为5 f$( e\+ +  
//default value of nSplitter is 5 hTkyz la  
this("","","",5); kfNWI#'9  
} M|-)GvR$J  
`oJ [u:b  
=N@t'fOr  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G$PE}%X  
{ =Qq+4F)MD  
sSiteURL= sURL; =a!=2VN9y  
sFilePath = sPath; iLT}oKF2N;  
sFileName = sName; P>L +t`'  
this.nSplitter = nSpiltter; 0(I j%Wi,  
a.'*G6~Qgw  
:N@^?q{b  
} dx]>(e@(t{  
!k%#R4*>  
^aQ"E9  
public String getSSiteURL() NI5``BwpO  
{ E]6 6]+;0_  
return sSiteURL; l%ZhA=TKQ  
} mmsPLv6  
e )ZUO_Q$  
BVm0{*-[|  
public void setSSiteURL(String value) @;kSx":b  
{ VpUAeWb  
sSiteURL = value; Al'3?  
} !BI;C(,RL  
S'14hk<  
WHI`/FM  
public String getSFilePath() /=h` L ,  
{ ;=@0'xPEa-  
return sFilePath; '|4!5)/K  
} eQ"E   
_U0f=m  
VX/#1StC  
public void setSFilePath(String value) i!cCMh8  
{ J;%Xfx]  
sFilePath = value; G`zm@QL  
} <Qq*p  
l@\FWWQ  
FqifriLN  
public String getSFileName() @6d[=!9  
{ IAEAhqp  
return sFileName; [2koe.?(  
} fatf*}eln  
|'.  
8[>zG2  
public void setSFileName(String value) W l1 6`9  
{ yBRC*0+Vy  
sFileName = value; {|\.i  
} iOdpM{~*  
B;WCTMy}  
Q &t<Y^B  
public int getNSplitter() Z= !*e~j@  
{ zT[!o j7  
return nSplitter; LF7SS;&~f  
} f-2c0Bi  
80;(Gt@<"  
kN>!2UfNS  
public void setNSplitter(int nCount) Sc   
{ akT6^cP^  
nSplitter = nCount; p:%loDk  
} {iLT/i%  
} i  LAscb  
l(q ,<[O  
-^57oU  
/* Z8oK2Dw  
**Utility.java ASfaX:ke  
*/ J$!iq|  
package NetFox; @A 5?3(e  
EIQ p>|5  
[9 RR8  
public class Utility { N?>vd*  
~,~eoW7  
JG,%qFlk  
public Utility() _l]fkk[T  
{ hzRYec(  
BSMwdr  
)/EO&F  
} ?rup/4|  
Bw{I;rW{2  
//线程睡眠 pD74+/DD  
public static void sleep(int nSecond) T5:G$-qL(  
{ [h:T*(R?  
try{ eN~=*Mn(za  
Thread.sleep(nSecond); 69 o 7EA  
} !3v1bGk  
catch(Exception e) Wr5V`sM  
{ TuYCR>P[  
e.printStackTrace (); D)'bH5  
} Z`BK/:vo3H  
} Ib0ZjX6  
BRYHX.}h\A  
//日志 zA"`!}*  
public static void log(String sMsg) _]*>*XfF(  
{ &yol_%C  
System.err.println(sMsg); TNr :pE<  
} eNu7~3k}  
OaZQ7BGq  
=6#Eh=7N  
public static void log(int sMsg) !&Pui{F  
{ K!]/(V(}  
System.err.println(sMsg); O<;3M'y\  
} - FlzEZ  
} o\)F}j&b#=  
@{pLk4E  
C=4Qlt[`  
/* wIBO ^w\J  
**TestMethod.java |qZ1|  
*/ Bn g@-#`/  
package NetFox; )D82N`c2\i  
#`X?=/q  
 {s{j~M  
public class TestMethod { !1Cy$}w  
QS]1daMIK<  
U2~kJ  
public TestMethod() d6sye^P  
{ ///xx/weblogic60b2_win.exe e,XYVWY%  
try{ _W'-+,  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :'&brp3ii=  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3J438M.ka  
SiteFileFetch fileFetch = new SiteFileFetch(bean); hzbw>g+  
fileFetch.start(); A:9?ZI/X  
} f[^Aw(o  
catch(Exception e){e.printStackTrace ();} 'W,jMju  
c>~*/%+  
m&?r%x  
} ["e3Ez  
o"BoZsMk  
@Sbe^x  
public static void main(String[] args) KX7 >^Bt&k  
{ tWa) _y  
new TestMethod(); X~,aNRy  
} WoRZW%  
} @qlK6tE`  
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