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http断点续传简单实现(java)

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/* wk[ wNIu  
**SiteFileFetch.java ^:cRp9l"7  
*/ '3;v] L?G  
package NetFox; 2 ZG@!Y|  
import java.io.*; JwP:2-o  
import java.net.*; Yx%bn?%;&  
!B^K[2`)N  
( ?Q|s,  
public class SiteFileFetch extends Thread { `s /?b|,  
YQVcECj  
fL6e?\Pw  
SiteInfoBean siteInfoBean = null; //文件信息Bean ?[TW<Yx  
long[] nStartPos; //开始位置 8^ #mvHah  
long[] nEndPos; //结束位置 j_Nm87i]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 n1J]p#nCa.  
long nFileLength; //文件长度 U^_D|$6  
boolean bFirst = true; //是否第一次取文件 fRHKQ(a#  
boolean bStop = false; //停止标志 hh"-w3+  
File tmpFile; //文件下载的临时信息 !OE*z $\  
DataOutputStream output; //输出到文件的输出流 IXq(jhm8bL  
CqoG.1jJS  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 2\@Z5m3B  
public SiteFileFetch(SiteInfoBean bean) throws IOException &/WAZs$2n  
{ _>_j\b  
siteInfoBean = bean; ];FtS>\x  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .v])S}K  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); <P4 FzK  
if(tmpFile.exists ()) >K)2NLW\xA  
{ EHI'xt  
bFirst = false; E*CcV;  
read_nPos(); GyC)EFd  
} .C!vr@@]  
else Q5n`F5   
{ nWaNT-  
nStartPos = new long[bean.getNSplitter()]; f_\_9o"l  
nEndPos = new long[bean.getNSplitter()]; R7_VXvm>z  
} z2 hFn&  
`_qK&&s  
{IM! Wb  
u, kU$  
} &ab|2*3?X  
1ThqqB  
pJ^NA2  
public void run() rAukHeH  
{ SbT5u3,'  
//获得文件长度 7P**:b  
//分割文件 \3zj18(@8!  
//实例FileSplitterFetch q,l)I+  
//启动FileSplitterFetch线程 Uems\I0  
//等待子线程返回 sqO< J$tz  
try{ 7"2b H  
if(bFirst) ?M}S| dsmE  
{ l-)B ivoi  
nFileLength = getFileSize(); Q*ju sm  
if(nFileLength == -1) 9 [Y-M  
{ C"eXs#A  
System.err.println("File Length is not known!"); QMp r v*i  
} 0b-?q&*_  
else if(nFileLength == -2) p]&j;H.  
{ wij,N(,H  
System.err.println("File is not access!"); GjT#%GBF  
} FN87^.^2S  
else MDO$m g  
{ PuCc2'#  
for(int i=0;i<nStartPos.length;i++) )&W**!(C  
{ 'Pd(\$ZY  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); p2O~>97t1  
} u$*>`Xe6  
for(int i=0;i<nEndPos.length-1;i++) nzsl@1s  
{ %J7UP4  
nEndPos = nStartPos[i+1]; .#w6%c@  
} lK(Fg  
nEndPos[nEndPos.length-1] = nFileLength; e XV@.  
} \k@$~}xD,  
} -n))*.V  
Z~u9VYi!  
uO(w1Q"^  
//启动子线程 B!S167Op  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )u} Q:`9  
for(int i=0;i<nStartPos.length;i++) {=Q7m`1  
{ _GA$6#]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ([E]_Q  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A o/vp-e  
nStartPos,nEndPos,i); Z S|WnMH  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M"Y0jQ(  
fileSplitterFetch.start(); "lVqU  
} l|"6yB |  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [M+tB"_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,T5u'";  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I0 Ia6w9  
nEndPos = " + nFileLength); ?ny =  
// fileSplitterFetch[nPos.length-1].start(); HZjf`eM,  
S\ ,mR4:  
4_=Ja2v8;`  
//等待子线程结束 nWYCh7  
//int count = 0; %JL]; 4'  
//是否结束while循环 KtN&,C )lJ  
boolean breakWhile = false; w=_Jc8/.  
"VUYh$=[  
! fl4"  
while(!bStop) dF@)M  
{ IApT'QNM  
write_nPos(); >,5i60Q  
Utility.sleep(500); [ !%R#+o=F  
breakWhile = true; u'5`[U -!  
2Aq~D@,9=:  
}VCI=?-  
for(int i=0;i<nStartPos.length;i++) ?UZ?NY  
{ Ao.\  
if(!fileSplitterFetch.bDownOver) `N8 7 h"  
{ blt'={Z?.x  
breakWhile = false; 8*a), 3aK  
break; pbk$o{$`W  
} l]Lx L  
} 4ne5=YY *  
if(breakWhile) 9<1F[SS<s9  
break; TJ_=1Y@z  
X` r* ob  
:}}%#/nd  
//count++; Qyh/ed/  
//if(count>4) kI\tqNJi  
// siteStop(); hf<J \   
} QfpuZEUK  
Hh[Tw&J4  
lFG9=Wf  
System.err.println("文件下载结束!"); Y%`SHe7M  
} 1T|$BK@)  
catch(Exception e){e.printStackTrace ();} 4`v!Z#e/aX  
} LDj<?'  
oOU1{[  
Pcd *">v  
//获得文件长度 0~WF{_0|  
public long getFileSize() J5p8nmb  
{ gBw^,)Q{0Y  
int nFileLength = -1; '?5j[:QY@  
try{ -apXI.  
URL url = new URL(siteInfoBean.getSSiteURL()); tD=@SX'Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L=!of{4Z(}  
httpConnection.setRequestProperty("User-Agent","NetFox"); NTs7KSgZ  
vp)Vb^K>  
/YKMKtE  
int responseCode=httpConnection.getResponseCode(); OYL]j{  
if(responseCode>=400) E#%}ZY  
{ S -&)p@4  
processErrorCode(responseCode); 9q[;u[A8^  
return -2; //-2 represent access is error W[''Cc.  
} !7p}C-RZp  
2b@tj 5  
|F$BvCg  
String sHeader; ,_v|#g@{  
n.6T OF  
iAn'aW\TF  
for(int i=1;;i++) Gpj* V|J  
{ pHE}ytcT  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Yc Q=vt{  
//Utility.log(in.readLine()); K`%tGVY  
sHeader=httpConnection.getHeaderFieldKey(i); _'0 @%P%  
if(sHeader!=null) X"asfA[6K  
{ },-*  
if(sHeader.equals("Content-Length")) Tenf:Hm/k  
{ wEft4 o  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'o4p#`R:8  
break; :*i f  
} {<$b Aj  
} f'En#-?O  
else <E,%@  
break; r|<DqTc6l  
} Ww3wsyx  
} 2B1xUj ]  
catch(IOException e){e.printStackTrace ();} yJx?M  
catch(Exception e){e.printStackTrace ();} VU.@R,  
>7Jr^o#|_x  
EM j;2!  
Utility.log(nFileLength); BzJ;%ywS  
A&5:ATQ/|  
. )XP\ m\  
return nFileLength; @I3eK^#|P  
} GRqT-/n"  
77 r(*.O|  
vG.9 H_&  
//保存下载信息(文件指针位置) T3%C%BcX  
private void write_nPos() 5r,r%{@K  
{ .10y0F L4  
try{ 8AFczeg[[  
output = new DataOutputStream(new FileOutputStream(tmpFile)); IND]j72  
output.writeInt(nStartPos.length); 9]'&RyH=#  
for(int i=0;i<nStartPos.length;i++) I~* ? d  
{ ( <*e  
// output.writeLong(nPos); R=j% S!  
output.writeLong(fileSplitterFetch.nStartPos); BHFY%6J!  
output.writeLong(fileSplitterFetch.nEndPos); }CGSEr4'w~  
} Cr ? 4Ngw  
output.close(); v}JD2.O+  
} cQj-+Tmu  
catch(IOException e){e.printStackTrace ();} +/{L#e>   
catch(Exception e){e.printStackTrace ();} H1:be.^YP  
} wNJzwC&iQ  
Vy<HA*  
xG2F!WeF  
//读取保存的下载信息(文件指针位置) o :q1beU  
private void read_nPos() t ~7V { xk  
{ z;\dL  
try{ bO5k6i  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w(d>HHg  
int nCount = input.readInt(); L5YnG_M&  
nStartPos = new long[nCount]; Ucw yxX I  
nEndPos = new long[nCount]; _Xcn N:Rt  
for(int i=0;i<nStartPos.length;i++) `\u;K9S6  
{ G bP!9I  
nStartPos = input.readLong(); [V8fu qE>  
nEndPos = input.readLong(); E-5_{sc  
} E ]9\R  
input.close(); F/c$v  
} (@0O   
catch(IOException e){e.printStackTrace ();} &[mZD,  
catch(Exception e){e.printStackTrace ();} ./6<r OW  
} 0C%W&;r0  
eJCjJ)  
6vKS".4C  
private void processErrorCode(int nErrorCode) una%[jTc  
{ nKr9#JebRC  
System.err.println("Error Code : " + nErrorCode); K4Dp:2/K%  
} |]=2 }%1w  
Q _iO(qu 6  
WG71k8af  
//停止文件下载 \G@wp5  
public void siteStop() Q^Ql\  
{  kzmQm  
bStop = true; I`(l*U  
for(int i=0;i<nStartPos.length;i++) G_H?f\/  
fileSplitterFetch.splitterStop(); VhGs/5  
/t<@"BoV  
m#/_x  
} <+j)P4O4  
} penlG36Q  
//负责部分文件的抓取 P,S G.EFK  
**FileSplitterFetch.java >ydRSr^  
*/ hg@}@Wq\)  
package NetFox; K0+.q?8D|  
E\ 8  
b,TiMf9},h  
import java.io.*; 1SIq[1  
import java.net.*; r,P1^uHx  
2aA`f7  
Uggw-sRU  
public class FileSplitterFetch extends Thread { ~tFqb<n  
<|Yj%f  
qZEoiNH(Tj  
String sURL; //File URL M6r^L6$N  
long nStartPos; //File Snippet Start Position wd@aw/  
long nEndPos; //File Snippet End Position ^rl"rEA  
int nThreadID; //Thread's ID s MN*RKer  
boolean bDownOver = false; //Downing is over r`S< A;  
boolean bStop = false; //Stop identical &ZHC-qMRK  
FileAccessI fileAccessI = null; //File Access interface )}%O>%  
AdZ;j6#  
s pLZ2]A  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #%@*p,xh  
{ nwt C:*}  
this.sURL = sURL; nP~({ :l8X  
this.nStartPos = nStart; `IpA.| Y  
this.nEndPos = nEnd; 5v\!]?(O;  
nThreadID = id; ma$Prd  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !}+tdT(y  
} |wE3UWsy  
|H}m4-+*  
2f`nMW  
public void run() YT/kC'A  
{ _/*U2.xS  
while(nStartPos < nEndPos && !bStop) ^>y@4qB  
{ 2 !" XzdD  
c)md  
$/1c= Y@  
try{ $2D uB  
URL url = new URL(sURL); )\;Z4x;]U  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i|)Su4Dw  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6&Juv  
String sProperty = "bytes="+nStartPos+"-"; 5m:i6,4  
httpConnection.setRequestProperty("RANGE",sProperty); L(>=BK*  
Utility.log(sProperty); g @I6$Z  
dUznxZB  
Hy"x  
InputStream input = httpConnection.getInputStream(); ,fIe&zq  
//logResponseHead(httpConnection); oY~ Dg  
~n')&u{  
Z4$cyL'$P  
byte[] b = new byte[1024]; [ =x s4=  
int nRead; 4F>Urh+  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t&Os;x?To?  
{ /y7M lU9  
nStartPos += fileAccessI.write(b,0,nRead); E@05e  
//if(nThreadID == 1) W>(/ bX  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ./j,Z$|  
} vzel#  
Y!q!5Crfi  
-V"22sR]  
Utility.log("Thread " + nThreadID + " is over!"); Hd7,ZHj3 ^  
bDownOver = true; I2$T"K:eo  
//nPos = fileAccessI.write (b,0,nRead); $GQ`clj<  
} _sE#)@p  
catch(Exception e){e.printStackTrace ();} @;xMs8@  
} I|-p3g8\  
} ?;YC'bF  
@pI5lh  
C'=k&#<-  
//打印回应的头信息 {y]mk?j  
public void logResponseHead(HttpURLConnection con) '$As<LOEd/  
{ Q(d9n8  
for(int i=1;;i++) rKHY?{!  
{ q{2I_[p  
String header=con.getHeaderFieldKey(i); }ZSQ>8a  
if(header!=null) ffXyc2o  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GT hL/M  
Utility.log(header+" : "+con.getHeaderField(header)); /:6Wzj  
else 6J~12TU,  
break; X1[CX&Am  
} j#~Jxv%n  
} 22<0DhJ  
?.c;oS|  
+#b:d=v!  
public void splitterStop() 0c.s -  
{ `s '#  
bStop = true; t&5%?QyM  
} be5,U\&z  
VN0mDh?E  
iV FkYx%}  
} nhSb~QqEh  
04%S+y.6&Y  
&|%6|u9  
/* ]`g <w#  
**FileAccess.java fl Jp4-nx  
*//文件访问(定位,写) YJs|c\eq?  
package NetFox; IC{eE  
import java.io.*; y~ G.V,0  
=Cv/Y%DN  
,<<4*  
public class FileAccessI implements Serializable{ p5O",3,A4  
bsxTqJ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #>Y'sd5'A  
RandomAccessFile oSavedFile; vhvdKD  
long nPos; 6*l^1;U  
cH<q:OYi  
gef6pfV  
public FileAccessI() throws IOException  `G1&Z]z  
{ 2eeQ@]Wj[Z  
this("",0); kVI#(uO  
} E$a ?LFa6  
(3[z%@I  
7@.cOB`y@3  
public FileAccessI(String sName,long nPos) throws IOException P3 c\S[F  
{ <]C$xp<2  
oSavedFile = new RandomAccessFile(sName,"rw"); Nf3.\eR  
this.nPos = nPos; Bb&^ {7  
oSavedFile.seek(nPos); G>YAJ o  
} (vR 9H(#  
a</D_66  
?Y:x[pOe  
public synchronized int write(byte[] b,int nStart,int nLen) ; )Kh;;e  
{ vN4Qdpdb  
int n = -1; =5D nR  
try{ PqNFyQkl  
oSavedFile.write(b,nStart,nLen); <)g8y A  
n = nLen; Ae^X35  
} @ZN^1?][  
catch(IOException e) 3$vRW.c\q  
{ Md)zEj`\  
e.printStackTrace (); !KKT[28v  
} 2=-utN@Z  
m6eZ_ &+u  
q0%  
return n; wn Y$fT9  
} at!Y3VywG  
l ?Y_~Wuw  
^^i6|l1  
} *?QE2&S:  
syx\gz  
G.+l7bnZM  
/* B) $c|dUV  
**SiteInfoBean.java WWwUwUi  
*/ a/~aFmu6b  
package NetFox; =k}SD96  
3`O?16O  
X u"R^  
public class SiteInfoBean { )f+U~4G&  
TUL_TR  
0Q"u#V Sp  
private String sSiteURL; //Site's URL @L84>3O  
private String sFilePath; //Saved File's Path #6+ FY+/  
private String sFileName; //Saved File's Name rA0,`}8\  
private int nSplitter; //Count of Splited Downloading File bf_I9Z3m  
NRnRMY-  
0U66y6  
public SiteInfoBean() -71dN0hWh  
{//nSplitter的缺省值为5 -B#yy]8  
//default value of nSplitter is 5  g]*  
this("","","",5); /Y[~-Y+!,  
} PI A)d-Z  
qo+N,x9o  
&m3.h!dq  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BE&B}LfvfO  
{ Xqp|VbDca  
sSiteURL= sURL; A]`El8_t"  
sFilePath = sPath; })vOaYT|-  
sFileName = sName; !.7udYmB  
this.nSplitter = nSpiltter; D0Z\Vvy  
He0=-AR8  
ufa41$B'yG  
} ]"AyAkT(  
QVZD/shq  
d "BW/%m|g  
public String getSSiteURL() @Un/c:n  
{ r#WT`pav  
return sSiteURL; va/m~k|i  
} HLQ"?OFlz  
w&Dv8Wv+Oq  
`T/~.`R  
public void setSSiteURL(String value) LW#M@  
{ SEQ%'E5-'  
sSiteURL = value; T1B|w"In  
} ZWc+),X  
s30 O@M))  
P7r'ffA  
public String getSFilePath() O9v_y+M+M  
{ Mr+@c)  
return sFilePath; < V\Y@Ei+  
} 7RU}FE  
~:;3uL s,8  
*, Ld/O;s  
public void setSFilePath(String value)  (dJI_A  
{ N\t1T(C|  
sFilePath = value; -0o[f53}p  
} Auy".br'  
'2J0>Bla  
/4=-b_2Y~  
public String getSFileName() y#ON|c /  
{ pl*~kG=  
return sFileName; rgIrr5  
} fLN!EDq  
VeiElU3  
&zL#hBE  
public void setSFileName(String value) Zr$d20M2A;  
{ (%ew604X  
sFileName = value; TGT$ >/w >  
} @mw "W{  
~CRSL1?  
(lA.3 4.p  
public int getNSplitter() VCNT4m  
{ Mro4`GL  
return nSplitter; NCeaL-y7  
} {!ZyCi19  
*E>.)B i  
!}TMiCK  
public void setNSplitter(int nCount) c"YXxA J  
{ g]mtFrP  
nSplitter = nCount; s}M= oe  
} cl[!`Z  
} #~:P}<h  
KcGsMPJ  
wn +FTqj  
/* +%J\y^09kr  
**Utility.java X[C3&NX#_  
*/ }6RT,O g  
package NetFox; 8$P>wCK\l  
LDT(]HJ  
ZU'!iU|8  
public class Utility { KV!<Oq  
AH7L.L+$M  
\L!uHAE2a  
public Utility() r2*<\ax  
{ Zp`T  
khd5 Cf[   
MKGS`X]<J  
} XaI;2fMGI  
AG"l1wz  
//线程睡眠 BW[5o3 i  
public static void sleep(int nSecond) >.9eBz@  
{ ( `' 8Ww  
try{ 8 ,}ikOZ?  
Thread.sleep(nSecond); #5CI)4x0!  
} Ayx^Wp*s  
catch(Exception e) Eyh|a. )-  
{ I %_MV  
e.printStackTrace (); ~2 }Pl)  
} <)m%*9{  
} ,4F,:w  
Evu=M-?  
//日志 _j#SpL'P  
public static void log(String sMsg) Rc$h{0K8  
{ 9w ~cvlv[  
System.err.println(sMsg); y>o>WN<q  
} V 2znU  
A=3HO\n5  
h* .w"JO  
public static void log(int sMsg) a0_(eO-S  
{ jp<VK<s]  
System.err.println(sMsg); $3 8gs{+  
} ~uaP$*B[  
} crmUrF#  
D5A=,\uk  
L'kq>1QWf  
/* 1M5 -pZ[D  
**TestMethod.java WYIw5 jzC  
*/ 7[o {9Yp&  
package NetFox; |HbEk[?^s  
(!zM\sF  
:$H!@n*/R  
public class TestMethod { Ti= 3y497S  
-CBD|fo[h  
YdOUv|tZC  
public TestMethod() }B)jq`a?|\  
{ ///xx/weblogic60b2_win.exe d'zT:g  
try{ aWvd`qA9r  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &hN,xpC  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fj=NiZ=  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9YC&&0 C@  
fileFetch.start(); pMN<p[MB  
} `SOhG?Zo  
catch(Exception e){e.printStackTrace ();} LM1b I4  
'j79GC0  
%W;u}`  
} k&GHu0z  
a!t V6H  
*T4ge|zUc  
public static void main(String[] args) 5u,sx664  
{ R;THA!  
new TestMethod(); JSjYC0e  
} q|{tQJfYg  
} Z{}+)Q*Q  
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