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http断点续传简单实现(java)

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/*  {I+   
**SiteFileFetch.java opxVxjTT#  
*/ rq?:I:0  
package NetFox; Qg;A (\z  
import java.io.*; 2*Hw6@Jj  
import java.net.*; Dw{rjK\TT'  
xO)vn\uJ  
}ozlED`E  
public class SiteFileFetch extends Thread { M-1 VB5  
yPrp:%PS  
l G12Su/  
SiteInfoBean siteInfoBean = null; //文件信息Bean 2:'C|  
long[] nStartPos; //开始位置 XlIRedZ{  
long[] nEndPos; //结束位置 .r[b!o^VR  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 6}wXNTd  
long nFileLength; //文件长度 H~E(~fl  
boolean bFirst = true; //是否第一次取文件 `RDl k  
boolean bStop = false; //停止标志 CAyV#7[0  
File tmpFile; //文件下载的临时信息 EM]~yn!+  
DataOutputStream output; //输出到文件的输出流 S'M=P_-7  
7^,C=2  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Ci6yH( RE  
public SiteFileFetch(SiteInfoBean bean) throws IOException HPl!r0 h  
{ 834(kw+#9  
siteInfoBean = bean; yL/EIN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); IB:eyq-+  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); XzI c<81Z  
if(tmpFile.exists ()) rB|Mp!g%@  
{ M,@\*qlEJ  
bFirst = false; {;0j9rr  
read_nPos(); 'WK}T)o  
} Qb}7lm{r  
else S!Ue+jW  
{ {|?OKCG{  
nStartPos = new long[bean.getNSplitter()]; ~ l"70\&  
nEndPos = new long[bean.getNSplitter()]; Cc*"cQe  
} wLwAtjW)  
wjh[}rTV*  
Nw ;BhBt  
fD+'{ivN4  
}  ^ZnlWZ@r  
vw=OGjT_>m  
.|Y2'TWQ  
public void run() 'W>Bz,M6yo  
{ 6*,'A|t?y  
//获得文件长度 -5,QrMM<  
//分割文件 eUlF4l<]  
//实例FileSplitterFetch !9=hUpRN  
//启动FileSplitterFetch线程 iTsmUq<b]l  
//等待子线程返回 ' 7G'R  
try{ pOP`n3m0  
if(bFirst) Q4e*Z9YJ  
{ Ug>yTc_(7  
nFileLength = getFileSize(); Z7RGOZQ}G  
if(nFileLength == -1) `:cnu;  
{ DpjiE/*  
System.err.println("File Length is not known!"); }[ LME Z  
} z-fP #.  
else if(nFileLength == -2) [uK*=K/v  
{ ] -"~?  
System.err.println("File is not access!"); s\ft:a@  
} $z,lq#zzl  
else t"M&Yy  
{ 0,+RF "R  
for(int i=0;i<nStartPos.length;i++) %T@3-V_  
{ gTWl];xja  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?B ; +,  
} G)5w_^&%  
for(int i=0;i<nEndPos.length-1;i++) ZN>oz@j Y  
{ GJz d4kj  
nEndPos = nStartPos[i+1]; Z$!>hiz2  
} B:S/ ?v  
nEndPos[nEndPos.length-1] = nFileLength; BwtjTwd  
} ucP}( $  
} &LM@_P"T  
,l`4)@{G  
x95[*[  
//启动子线程 t mAj  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g a|RW0  
for(int i=0;i<nStartPos.length;i++) ,!+>/RlJ  
{ m<L.H33'  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rT$J0"*=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =9$hZ c  
nStartPos,nEndPos,i); gi!{y   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2mUq$kws  
fileSplitterFetch.start(); SK f9 yS#  
} ut z.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =" Q5Z6W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lZoy(kdc  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \.h!'nfF  
nEndPos = " + nFileLength); Xv ;} !z  
// fileSplitterFetch[nPos.length-1].start(); sYnf #'  
XnC`JO+7M  
2eErvfC[  
//等待子线程结束 YEfa8'7R  
//int count = 0; w@&g9e6E  
//是否结束while循环 ph\KTLU  
boolean breakWhile = false; 0>hV?A  
F FHk0!3  
P,5gaT)  
while(!bStop) J6pQ){;6  
{ q]Y [W1  
write_nPos(); 4oW6&1  
Utility.sleep(500); Y1 RiuJtL  
breakWhile = true; ?EP>yCR9  
BR\3ij  
qr>:meJy4  
for(int i=0;i<nStartPos.length;i++) R'R LF =  
{ Hq9yu*!u  
if(!fileSplitterFetch.bDownOver) ;xF5P'T?|  
{ ~=HrD?-99p  
breakWhile = false; 1.\|,$  
break; 3S4'x4*  
} 5J!ncLNm{  
} H9nVtS{x  
if(breakWhile) 9W{`$30  
break; LASR*  
.)Xyz d  
g/H:`J  
//count++; <vS J< WY  
//if(count>4) S[p.`<{J  
// siteStop(); 7_t\wmvYp  
} +$Q.N{LV  
,<iJ#$: Sx  
!YD~o/t@|  
System.err.println("文件下载结束!"); EHpIbj;n  
} Y r3h=XY  
catch(Exception e){e.printStackTrace ();}  CZ&VP%  
} PDN3=PAR/A  
.48Csc-  
5 :O7cBr  
//获得文件长度 m$nT#@l5bH  
public long getFileSize() C1=7.dPr  
{ s;oDwT1  
int nFileLength = -1; i=b<Mz7|  
try{ s9t`!  
URL url = new URL(siteInfoBean.getSSiteURL()); T)%34gN  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [I/f(GK  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4`Com~`6"  
Y1 e>P  
r!Ujy .R  
int responseCode=httpConnection.getResponseCode(); {2u#Q 7]|  
if(responseCode>=400) aLr\Uq,83  
{ m1,?rqeb  
processErrorCode(responseCode); 9qyA{ |3  
return -2; //-2 represent access is error yEYlQ=[#  
} OVr, {[r  
TR2X' `:O  
CX](^yU_  
String sHeader; CKJ9YKu{W  
/8V#6d_  
Jpi\n- d!  
for(int i=1;;i++) "[ f"h  
{ 32DT]{-N!  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3;fuz Kk@b  
//Utility.log(in.readLine()); osKM3}Sb  
sHeader=httpConnection.getHeaderFieldKey(i); z [xi  
if(sHeader!=null) vZEeb j  
{ "Mt4~vy  
if(sHeader.equals("Content-Length")) W i a%rm  
{ `-)!4oJ]  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _Wcr'*7  
break; }e}J6 [wP  
} H(qDQqJHYy  
} W<Ms0  
else 7:fC,2+  
break; 0bY}<x(;  
} 4;G:.k!K  
} :?1r.n  
catch(IOException e){e.printStackTrace ();} J*)Vpk  
catch(Exception e){e.printStackTrace ();} CiE  
h-0sDt pR  
'FB?#C%U  
Utility.log(nFileLength); 6=V&3|"  
T /iKz  
Yh`P+L  
return nFileLength; p-]vf$u  
} &\(p<TF  
W/*2I3a  
,TrrqCw>  
//保存下载信息(文件指针位置) dP8b\H  
private void write_nPos() $umh&z/  
{ WfbG }%&J  
try{ Y02 cX@K6  
output = new DataOutputStream(new FileOutputStream(tmpFile)); SKTf=rY  
output.writeInt(nStartPos.length); 5<o8prt B  
for(int i=0;i<nStartPos.length;i++) >T*/[{L8;  
{ U68o"iE  
// output.writeLong(nPos); lR5< G  
output.writeLong(fileSplitterFetch.nStartPos); Wn*>h'R  
output.writeLong(fileSplitterFetch.nEndPos); +5n,/YjS`  
} xO8-vmf2  
output.close(); :1Jg;G  
} #{973~uj  
catch(IOException e){e.printStackTrace ();} Xg>nb1e  
catch(Exception e){e.printStackTrace ();} R"Q=U}?$  
} \x JGR!  
.h)o\6Wq  
uyr56  
//读取保存的下载信息(文件指针位置) 9 yH/5'  
private void read_nPos() <gU^#gsGra  
{ X"V,3gDG  
try{ ImJ2tz6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P,xI3U< q  
int nCount = input.readInt(); T7f>u}T  
nStartPos = new long[nCount]; IipG?v0z~  
nEndPos = new long[nCount]; #]nH$Kq  
for(int i=0;i<nStartPos.length;i++) sFNBrL  
{ }Dk*Hs^E  
nStartPos = input.readLong(); H8[ L:VeNT  
nEndPos = input.readLong(); Fb#_(I[aj  
} wLeP;u1  
input.close(); 8l(_{Y5(-  
} fVCpG~&t  
catch(IOException e){e.printStackTrace ();} w_-v!s2  
catch(Exception e){e.printStackTrace ();} }S{#DgZ@X  
} RhVQVjc  
8BUPvaP<[  
 m9My  
private void processErrorCode(int nErrorCode) '~?\NeO=  
{ h-B&m:gD_U  
System.err.println("Error Code : " + nErrorCode); zZ3Ko3L%g_  
} ,DrE4")4  
GC(:}e|  
96fzSZS,  
//停止文件下载 CB(Qy9C%h[  
public void siteStop() 02Z># AE  
{ 2/.E uf   
bStop = true; n6T@A;_g  
for(int i=0;i<nStartPos.length;i++) qsnZ?hXPp  
fileSplitterFetch.splitterStop(); -h&AO\*^W  
>;Er[Rywr  
mSSDV0Pfn  
} `9;:mR $  
} ^6=y4t=%F  
//负责部分文件的抓取 Y*-#yG9  
**FileSplitterFetch.java H.sHXuu  
*/ JTuU}nm+  
package NetFox; {"< D$*K~  
$bQ[H[4l  
@di mZsi1  
import java.io.*; . IBy'  
import java.net.*; ;0lHi4 c0  
+an.z3?w  
BM+v,hGY  
public class FileSplitterFetch extends Thread { Q[t|+RNKv2  
Bny3j~*U  
ZTV|rzE   
String sURL; //File URL ,k}-I65M*t  
long nStartPos; //File Snippet Start Position @ToY,@]e  
long nEndPos; //File Snippet End Position a6AD`| U8  
int nThreadID; //Thread's ID rt+%&% wt  
boolean bDownOver = false; //Downing is over 9&R. <I  
boolean bStop = false; //Stop identical m,i@  
FileAccessI fileAccessI = null; //File Access interface > sW9n[  
3ifQKKcR{  
#'}?.m  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Zo}O,;(F5  
{ .W _'6Q+  
this.sURL = sURL; P@ Oq'y[  
this.nStartPos = nStart; i v7^ !  
this.nEndPos = nEnd; I5[HD_g:  
nThreadID = id; >BU"C+a8g  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,DUD4 [3  
} 9 06b=  
wO6 D\#  
@BbqYX  
public void run() Wr.G9zq.+  
{ tz #Fy?pe  
while(nStartPos < nEndPos && !bStop) 6?an._ C  
{ %3B0s?,I  
!9yOFd_  
dQSX&.<c,  
try{ 5>{S^i~!  
URL url = new URL(sURL); 4-RzWSFbo`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @J"Gn-f~  
httpConnection.setRequestProperty("User-Agent","NetFox"); L4bx [  
String sProperty = "bytes="+nStartPos+"-"; "<f"r#   
httpConnection.setRequestProperty("RANGE",sProperty); '1|FqQ\.  
Utility.log(sProperty); +AGI)uQQ  
iTf]Pd'  
Ae,P&(  
InputStream input = httpConnection.getInputStream(); |KF_h^  
//logResponseHead(httpConnection); =+{SZh@  
X6lkz*M.  
(* WO<V  
byte[] b = new byte[1024]; [ +w=  
int nRead;  u>R2:i  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I_|@Fn[>  
{ C"`,?K(U  
nStartPos += fileAccessI.write(b,0,nRead); 9?8Yf(MC%u  
//if(nThreadID == 1) n o6q3<re  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *&7F(  
} H_H3Gp  
O}Y& @V%4k  
~4e4G yx c  
Utility.log("Thread " + nThreadID + " is over!"); mQ# 0c_  
bDownOver = true; p:kHb@  
//nPos = fileAccessI.write (b,0,nRead); -:mT8'.F-  
} 'Em5AA`>  
catch(Exception e){e.printStackTrace ();} WCf?_\cG  
} (^x ,  
} /l o;:)AiP  
?)x"+[2  
hzG+s#  
//打印回应的头信息 >NL4&MV:  
public void logResponseHead(HttpURLConnection con) $9LI v  
{ 7OF6;@<  
for(int i=1;;i++) zQpF, N<b  
{ 5,H,OZ}  
String header=con.getHeaderFieldKey(i); 6|h~pH  
if(header!=null) 46 p%y  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &-l(nr]h]  
Utility.log(header+" : "+con.getHeaderField(header)); A.`) 0dV  
else -u!{8S~wA  
break; ZdcG6IG+  
} "n,? )  
} y2nwDw(xF  
Pe-1o#7~W  
ElBpF8xJ|o  
public void splitterStop() QQ1|]/)  
{ CF|4, K)  
bStop = true; &x= PAu  
} t|/{oAj  
d~ m,hCTe  
?4G/f<ou  
} HN7C+e4U~  
E@uxEF  
-SF *DZ  
/* ~57.0?IK  
**FileAccess.java l)1FCDV  
*//文件访问(定位,写) x^0MEsR  
package NetFox; rV *`0hA1  
import java.io.*; 'WF Ey>1#  
_VvXE572  
B)^uGS W  
public class FileAccessI implements Serializable{ -pb>=@Yq  
)I/K-zj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \%=GM J^[p  
RandomAccessFile oSavedFile; y5oC|v7  
long nPos; B<et&r;  
$7\!  
g#??Mz   
public FileAccessI() throws IOException .=I:cniw\r  
{ }{3XbvC  
this("",0); BRSOE U\=  
} oQsls9t  
'h]sq {  
!:zWhu,  
public FileAccessI(String sName,long nPos) throws IOException Imv ]V6"D=  
{ zG"*B_l}+  
oSavedFile = new RandomAccessFile(sName,"rw"); Qj:`[#3?2  
this.nPos = nPos; reO^_q'  
oSavedFile.seek(nPos); J ~"h&>T  
} CVk.Ez6  
q!r4"#Y"@Z  
L("zS%qr  
public synchronized int write(byte[] b,int nStart,int nLen) 8Qwn  
{ #YEOY#  
int n = -1; uaiCyh1:  
try{ x JXPtm  
oSavedFile.write(b,nStart,nLen); .66_g@1  
n = nLen; dc]D 8KX  
} ,p3moD 3  
catch(IOException e) cz{5-;$9Z  
{ TmH'_t.*T~  
e.printStackTrace (); y,YK Mc  
} S(&]?!  
J/-&Fa\(  
IN{ 1itE  
return n; -JMlk:~  
} j$%uip{  
#z. QBG@  
krt8yAkG  
} y?r:`n  
v c r5  
/a'cP  
/* I7[F,xci  
**SiteInfoBean.java JsDugn ,B  
*/ e [}m@a  
package NetFox; BZdryk:S  
Pl9Ky(Q`V  
Ho_ 2zx:8b  
public class SiteInfoBean { m h5ozv$  
ytsPk2@WR  
SniKC qmC]  
private String sSiteURL; //Site's URL 0Qa kFt  
private String sFilePath; //Saved File's Path =xf7lN'  
private String sFileName; //Saved File's Name C{5^UCJkg  
private int nSplitter; //Count of Splited Downloading File |1rKGDc  
q%rfKHMA50  
XH"-sZt  
public SiteInfoBean() M8,_E\*  
{//nSplitter的缺省值为5 (*XSr Q  
//default value of nSplitter is 5 2)W~7GED  
this("","","",5); <* 4'H  
} XZ3)gYQi  
E\GD hfTQ  
9^AfT>b~f  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eHt |O~  
{ --t5jSS44  
sSiteURL= sURL; .3Ag6YI0N  
sFilePath = sPath; Z: e|~#  
sFileName = sName; @C=Dk  
this.nSplitter = nSpiltter; `g~T #U\>d  
S,'y L7s  
~"t33U6  
} s/" l ?d  
;O Td<  
?)2&LVrf  
public String getSSiteURL() D{Rk9MKkE  
{ >&`S$1 o  
return sSiteURL; m:sT)  
} p2\mPFxEP  
FK:Tni  
\{Yi7V Xv  
public void setSSiteURL(String value) .dr-I7&!  
{ tt%lDr1A)  
sSiteURL = value; U> @st="  
} h M/:zC:  
%^){)#6w  
>bo_  
public String getSFilePath()  55<f  
{ eX1<zzd  
return sFilePath; Px$4.b[{_Y  
} fz hCV  
<,Z6=M`  
"F.0(<4)  
public void setSFilePath(String value) TSPFi0PP  
{ lZI?k=rWv  
sFilePath = value; m%[Ul@!V  
} MD 62ObK!  
= ;!$Qw4  
jJ B+UF=  
public String getSFileName() = MP?aH [  
{ ;%/Kh :Vg  
return sFileName; b;AGw3SF  
} e 2@{Ab  
i!U,qV1  
W-ctx"9DS  
public void setSFileName(String value) k>ERU]7[  
{ GCEcg&s=\S  
sFileName = value; T`?{Is['(  
} V7pe|]%r  
{~lVe GBp  
RdtF5#\z  
public int getNSplitter() ;rK= jz^Q  
{ %xH2jf  
return nSplitter; =HGC<#  
} js~?y|e8k  
7H~J?_  
ap7ZT7KW  
public void setNSplitter(int nCount) a'U}.w}  
{ /%P|<[< [  
nSplitter = nCount; x_yQoae  
} $^ wqoW%t  
}  #"6O3.P  
c[h{C!d1  
DviRD[+q"  
/* Ns*&;x9  
**Utility.java aJmSagr69C  
*/ rda/  
package NetFox; R[l9f8  
.>.B  
NukcBH  
public class Utility { .0[ zZ  
x  bsk  
8^8fUN4<=  
public Utility() RF,[1O-\O  
{ Vh1R!>XY  
Qel2OI`b  
+5>*$L%8T`  
} cKbjW  
X/8CvY#n  
//线程睡眠 Bj-80d,  
public static void sleep(int nSecond) Wvg+5Q  
{ &:3uK`  
try{ t04_~e  
Thread.sleep(nSecond); bu j}pEI  
} W'B=H1  
catch(Exception e) ?c$z?QTMJ  
{ k /hD2tBLu  
e.printStackTrace (); de&*#O5  
} zOEdFU{x  
} R;6$lO8C&  
\m\E*c ):  
//日志 PqhR^re0.  
public static void log(String sMsg) %O=U|tuc$  
{ !(-lY(x  
System.err.println(sMsg); gYtv`O  
} *j9hjq0j  
Hw(_l,Xf  
Ui^~A  
public static void log(int sMsg) zn=Ifz)#|  
{ YEg(QOn3Q  
System.err.println(sMsg); =.sg$VX  
} 2%|0c\y|z=  
} mHiV};$  
S1!X;PP/  
z;#DX15Rj  
/* ^~iFG+g5  
**TestMethod.java tz).]E D  
*/ 8c6dTT4  
package NetFox; qir/Sa' [  
4IT`8n~  
(iT?uMRz  
public class TestMethod { 5f` a7R  
GmONhh(k  
lVw77bZ  
public TestMethod() >Z\{P8@k0  
{ ///xx/weblogic60b2_win.exe YM:;mX5B  
try{ '1jG?D  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3>+9Rru  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r&MHww1i  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 24}?GO  
fileFetch.start(); S~ff<A>f  
} b,k%n_&n  
catch(Exception e){e.printStackTrace ();} rmzM}T\20  
Ub(8ko:8$  
nQ$4W  
} {#Lj,o  
LhfI"fc  
na5:)j4<  
public static void main(String[] args) j.b7<Vr4;  
{ h0=Q.Yz6  
new TestMethod(); (F<VcB  
} 0Bo7EV  
} ?tf/#5t}  
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