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http断点续传简单实现(java)

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/* m1Ya  
**SiteFileFetch.java 4=Ru{ewRV  
*/ xL"J?Gy  
package NetFox; ~44u_^a  
import java.io.*; az0=jou<Zl  
import java.net.*; aH'fAX0bF  
9]oT/ooM  
BoYY^ih  
public class SiteFileFetch extends Thread { v7wyQx+Q  
;WX.D]>{W  
Yr_ B(n  
SiteInfoBean siteInfoBean = null; //文件信息Bean xsj ,l@Ey  
long[] nStartPos; //开始位置 K6p\ >J  
long[] nEndPos; //结束位置 nsU7cLf"^V  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 m[v0mXE  
long nFileLength; //文件长度 klT?h[I!  
boolean bFirst = true; //是否第一次取文件 `D~oY=  
boolean bStop = false; //停止标志 l_Lz9k  
File tmpFile; //文件下载的临时信息 Y $v#>w_M  
DataOutputStream output; //输出到文件的输出流 jeRE(3'Q  
Y^!qeY  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) SefhOh^,V  
public SiteFileFetch(SiteInfoBean bean) throws IOException @M4c/k}  
{ Xpg -rxX  
siteInfoBean = bean; .eD&UQ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); jsE8=zZs  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); lt6wmCe  
if(tmpFile.exists ()) "gM!/<~  
{ Za|iU`e\  
bFirst = false; C78g|n{  
read_nPos(); |nx3x  
} xz!0BG  
else w)+1^eW  
{ AYfOETz  
nStartPos = new long[bean.getNSplitter()]; Cy$~H  
nEndPos = new long[bean.getNSplitter()]; 63=&??4  
} p;}`PW  
=|1_6.tz  
O|8@cO  
@u9L+*F  
} `~)?OTzU#  
?DUim1KG  
#RR;?`,L}  
public void run() t"GnmeH i  
{ 4uOR=+/l  
//获得文件长度 |JIlp"[  
//分割文件 ZL<X* l2  
//实例FileSplitterFetch F8-GnT xa  
//启动FileSplitterFetch线程 %"mI["{  
//等待子线程返回 q*&H  
try{ &@oI/i&0B  
if(bFirst) ]j>xQm\  
{ uK"  T~  
nFileLength = getFileSize(); oqF?9<Vgc,  
if(nFileLength == -1) %akW43cE  
{ GuR^L@+ -.  
System.err.println("File Length is not known!"); PzSL E>Q  
} {TNORbZz  
else if(nFileLength == -2) U,i_}O3Q  
{  (yP1}?  
System.err.println("File is not access!"); d9v66mpJM  
} kiM:(=5  
else LP#wE~K"b  
{ Eu(Qe ST\  
for(int i=0;i<nStartPos.length;i++) U| Fqna  
{ v3Vve:}+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); i&>^"_4rc  
} }jCO@v;  
for(int i=0;i<nEndPos.length-1;i++) i;^lh]u  
{ +=E\sEe  
nEndPos = nStartPos[i+1]; vK)'3%  
} Zo&i0%S\E  
nEndPos[nEndPos.length-1] = nFileLength; i-v: %  
} R %RbC!P  
} >JE+j=  
T4.wz 58  
;99oJD,  
//启动子线程 c rb^TuN  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rt*x[5<  
for(int i=0;i<nStartPos.length;i++) 8 8_ef7w  
{ b:F;6X0~Hl  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PEvY3F}_rh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [oU\l+t  
nStartPos,nEndPos,i); f5 bq)Pm&  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Uyb0iQ-,s  
fileSplitterFetch.start(); iZn0B5]ikj  
} x>EL|Q=?  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L3Y,z3/  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;9z|rWsF  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *G.vY#h  
nEndPos = " + nFileLength); b V  EJ  
// fileSplitterFetch[nPos.length-1].start(); %RV81H9B  
2QaE&8vW  
~_EDJp1J  
//等待子线程结束 >p-UQc  
//int count = 0;  6a,8t  
//是否结束while循环 o664b$5nsI  
boolean breakWhile = false; :%sBY0 yF  
gf8o~vKX$G  
%evb.h)  
while(!bStop) aNu.4c/5  
{ \09A"fs{  
write_nPos(); fVn4=d6X  
Utility.sleep(500); 06Wqfzceb  
breakWhile = true; %9>w|%+;U+  
F@Sk=l(  
z<55[~3  
for(int i=0;i<nStartPos.length;i++) F&wAre<  
{ =8 @DYz'  
if(!fileSplitterFetch.bDownOver) N[W#wYbH  
{ 0C :8X   
breakWhile = false; j_g(6uZhz3  
break; j ^j"w(a  
} XF(D%ygeC  
}  =Iop  
if(breakWhile) myfTz tJ  
break; 6{.U7="  
eB#I-eD  
qg#YQ'vWte  
//count++; Un K7&Uo  
//if(count>4) a 4ViVy  
// siteStop(); ]\^O(BzB  
} {BJ>x:2  
]Y I9  
eX#.Zt]  
System.err.println("文件下载结束!"); 9o>D Uc  
} CPy>sV3Ru0  
catch(Exception e){e.printStackTrace ();} Z4/D38_  
} &/U fXKr  
+45SKu=  
c~(61Sn]  
//获得文件长度 q{&c?l*2  
public long getFileSize() oH=?1~ e  
{ D-{*3?x  
int nFileLength = -1; gPCf+>X{  
try{ 4ekwmw(ox  
URL url = new URL(siteInfoBean.getSSiteURL()); Cl&mz1Y;]1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4E.9CjN1>  
httpConnection.setRequestProperty("User-Agent","NetFox"); ppz3"5  
%l!A%fn(  
imif[n+]}d  
int responseCode=httpConnection.getResponseCode(); l[i4\ CT  
if(responseCode>=400) \#%GVru!  
{ 23r(4  
processErrorCode(responseCode); qj _0 td$  
return -2; //-2 represent access is error ~b]enG5xS4  
} >gp53\  
&7\}S qp  
wIi(\]Q  
String sHeader; Dazm8_x  
t)W=0iEd9  
jm%s#`)g  
for(int i=1;;i++) K^<?LXJF  
{ H[.)&7M\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;&=jSgr8  
//Utility.log(in.readLine()); SN@>mpcJS  
sHeader=httpConnection.getHeaderFieldKey(i); -OJ<Lf+"=  
if(sHeader!=null) !+3&%vQ)  
{ U3&GRY|##  
if(sHeader.equals("Content-Length")) `C: 7 N=9  
{ D'!JV1Q  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gamB]FPZ  
break; s\mA3t  
} 8:& ! F`o  
} < +*  
else =,zB|sjn  
break; P+f}r^4}  
} Kfb(wW  
} FUL3@Gb$UV  
catch(IOException e){e.printStackTrace ();} ({rcH.:  
catch(Exception e){e.printStackTrace ();} DRm`y>.  
lU!_V%n  
`_cv& "K9f  
Utility.log(nFileLength); -crMO57/  
a&JY x  
3}\z&|  
return nFileLength; /g>-s&w  
} y%vAEQ2j=  
q`p0ul,n  
)] q Qgc&  
//保存下载信息(文件指针位置) ?rOj?J9  
private void write_nPos() `WH$rx!  
{ 2+y wy^  
try{ i ed 1+H  
output = new DataOutputStream(new FileOutputStream(tmpFile)); >g !Z|ju  
output.writeInt(nStartPos.length); H_f8/H  
for(int i=0;i<nStartPos.length;i++) ?S& yF  
{ p7> 9 m  
// output.writeLong(nPos); % WDTnEm  
output.writeLong(fileSplitterFetch.nStartPos); .iR<5.  
output.writeLong(fileSplitterFetch.nEndPos); Nsh/  
} *e [*  
output.close(); (km $qX  
} XdA]);,  
catch(IOException e){e.printStackTrace ();} I<RARB-j  
catch(Exception e){e.printStackTrace ();} NB<8M!X/  
} ?<4pYEP  
b * \ oQ  
Ry}4MEq]  
//读取保存的下载信息(文件指针位置) 2fky z  
private void read_nPos() &*/= `=:C8  
{ uT=r*p(v  
try{ S8AbLl9G@>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T P#Ncqh  
int nCount = input.readInt(); Io<T'K  
nStartPos = new long[nCount]; "Q+wO+}6  
nEndPos = new long[nCount]; ZB1%Kn#zo4  
for(int i=0;i<nStartPos.length;i++) (5] [L<L  
{ IN3-ZNx  
nStartPos = input.readLong(); (pCHj'  
nEndPos = input.readLong(); ffk >IOH  
} w!<e#Z]3b  
input.close(); !x-__[#  
} 3M?O(oO  
catch(IOException e){e.printStackTrace ();} OP+*%$wR  
catch(Exception e){e.printStackTrace ();} %|x9C,0p#  
} u\ 7Y_`8  
JJ1>)S}X-  
Q^va +O  
private void processErrorCode(int nErrorCode) !+$QN4{9  
{ ;5;>f)diS  
System.err.println("Error Code : " + nErrorCode); l4$ sku-  
} L *\[;.mk  
9j^rFG!n  
1d+Kn Jy  
//停止文件下载 9LPXhxNwB  
public void siteStop() @BLB.=  
{ &iu]M=Y b  
bStop = true; >k\p%{P  
for(int i=0;i<nStartPos.length;i++) }ACg#;>/+  
fileSplitterFetch.splitterStop(); X,+a 6F  
qQ]fM$!  
~m<K5K6 V  
} (t3gNin  
} H.iCYD_=  
//负责部分文件的抓取 > A@yF?  
**FileSplitterFetch.java 8Ckd.HKpQ  
*/ +a,#BSt  
package NetFox; dpE^BWv3  
Hc8^w6S1@  
82 |^o  
import java.io.*; &bJBsd@Os  
import java.net.*; R%r25_8  
eb}XooX  
q'7.lrKwa>  
public class FileSplitterFetch extends Thread { f%n ;Z}=  
Q1*_l  
}>AA[ba"'  
String sURL; //File URL |8{ k,!P'K  
long nStartPos; //File Snippet Start Position v(0ujfSR0  
long nEndPos; //File Snippet End Position au19Q*r9  
int nThreadID; //Thread's ID cg^~P-i@*  
boolean bDownOver = false; //Downing is over "4xo,JUf  
boolean bStop = false; //Stop identical .= ~2"P  
FileAccessI fileAccessI = null; //File Access interface ).GM 0-y  
TR*vZzoy  
lE%KzX?&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H/`@6, j  
{ A- m IWTa  
this.sURL = sURL; o_=4Ex "  
this.nStartPos = nStart; @Oz3A<M  
this.nEndPos = nEnd; NApy(e 5%  
nThreadID = id; 19[oXyFI  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _l] 0V g`  
} D]fgBW-  
.nEMd/pX  
fz VN;h  
public void run() Muq~p~m}  
{ WU=EJY}#n  
while(nStartPos < nEndPos && !bStop) ;Q&9 t  
{ :''Swi<H  
pRlScD_};  
s\~j,$Mm2  
try{ .KG9YGL#  
URL url = new URL(sURL); cV1E<CM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2s,cyCw&  
httpConnection.setRequestProperty("User-Agent","NetFox"); e/x 9@1s#  
String sProperty = "bytes="+nStartPos+"-"; #F3'<(j  
httpConnection.setRequestProperty("RANGE",sProperty); <i ]-.>&J  
Utility.log(sProperty); s^6,"C  
2N |iOog  
ODKh/u_  
InputStream input = httpConnection.getInputStream(); +8 "8s  
//logResponseHead(httpConnection); tUJe-3,  
R-W.$-rF  
r/':^Ex  
byte[] b = new byte[1024]; ,hJx3g5#n  
int nRead; WoN JF6=?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JXww_e[  
{ HD{u#~8{  
nStartPos += fileAccessI.write(b,0,nRead); 3&E@#I^] ,  
//if(nThreadID == 1) IDF0nx]  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); . WJ  
} Q~ Nq5[  
R$IsP,Uw  
e\aW~zs 2  
Utility.log("Thread " + nThreadID + " is over!"); ;B2&#kot7  
bDownOver = true; 0H%zkJ>Q  
//nPos = fileAccessI.write (b,0,nRead); ro?.w  
} Zw4%L?   
catch(Exception e){e.printStackTrace ();} pHoxw|'Y  
} FeZWS>N  
} )#4(4 @R h  
jC:D>  
N0$ uB"  
//打印回应的头信息 z*b|N45O  
public void logResponseHead(HttpURLConnection con) wZCboQ,  
{ Fsq)co  
for(int i=1;;i++) 9X1vL  
{ c*axw%Us  
String header=con.getHeaderFieldKey(i); h7.jWJTo  
if(header!=null) 8?'=Aeo  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;){ZM,Ox  
Utility.log(header+" : "+con.getHeaderField(header)); ]fh(b)8_,  
else I5[@C<b  
break; Je"XIhBr  
} :qR8 e J  
} dR>$vbjh1Z  
|FaK =e  
j5n"LC+oz  
public void splitterStop() s)3CosU  
{ o ,_F;ZhE  
bStop = true; WFFd3TN%<  
} pcOKC0b.  
ZF#lh]  
e{4e<hd  
} d6m&nj  
1W0[|Hf2v*  
;*nzb!u\\  
/* DH$Nz  
**FileAccess.java K'Wv$[~Dc  
*//文件访问(定位,写) Z3Ww@&bU  
package NetFox; .!2 u#A  
import java.io.*; R vU'8Y?>w  
/IX555/dR1  
pFu!$.Fr  
public class FileAccessI implements Serializable{ JAMV@  
=SW<Vhtb  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %@aC5^Ovy+  
RandomAccessFile oSavedFile; Wy1.nn[  
long nPos; Kn?h  
m,6u+Z ,  
.A/xH x  
public FileAccessI() throws IOException 8{icY|:MTN  
{ .DnG}884  
this("",0);  cFjD*r-  
} zw5Ol%JF  
A'u]z\&%c  
-m=!SQ >9  
public FileAccessI(String sName,long nPos) throws IOException aAd1[?&  
{ KG(l=? N  
oSavedFile = new RandomAccessFile(sName,"rw"); ,N_V(Cx5pt  
this.nPos = nPos; !w!k0z]  
oSavedFile.seek(nPos); % bdBg  
} _D+J3d(Pjk  
DV({! [EP  
`4Z:qh+fJ  
public synchronized int write(byte[] b,int nStart,int nLen) NVom6K  
{ z}r  
int n = -1; z^/9YzA!6  
try{ Lcy6G%A  
oSavedFile.write(b,nStart,nLen); Sy*p6DP  
n = nLen; j,i)ecZ>  
} DbR!s1ux  
catch(IOException e) <ZO+e*4  
{ FKf2Q&2I  
e.printStackTrace (); :UKc:JVNM  
} 6RSit  
ZRr.kN+F  
YoQQ ,  
return n; mZ?QtyljT  
} vQoZk,  
7a/ BS(kq<  
&u<%%b|  
} d?/g5[  
J-klpr#  
R$eEW"]  
/* 7coVl$_Zl  
**SiteInfoBean.java zqXDD; w3  
*/ r#}o +3*  
package NetFox;  = ~*Vfx  
O ~[[JAi[  
_3g!_  
public class SiteInfoBean { "-IF_Hid  
.%0a  
olHmRJ  
private String sSiteURL; //Site's URL NQOf\.#g  
private String sFilePath; //Saved File's Path (\ |Go-2G  
private String sFileName; //Saved File's Name rof9Rxxe-  
private int nSplitter; //Count of Splited Downloading File  ME5M;bz(  
PyQ\O*  
d7Cs a c  
public SiteInfoBean() c[vFh0s"m  
{//nSplitter的缺省值为5 BryD?/}P)M  
//default value of nSplitter is 5 J'&K  
this("","","",5); 4^ 0CHy  
} !Ap*PL  
!"F8jA}  
urL@SeV+$  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PVQn$-aq1  
{ EyV5FWb58  
sSiteURL= sURL; &-vHb   
sFilePath = sPath; YQ1rS X3  
sFileName = sName; %r(qQM.Pl  
this.nSplitter = nSpiltter; SapVS*yx@  
vZqW,GDfXo  
cwHbm%  
} :pvVm>  
]% G#x  
[KW)z#`*  
public String getSSiteURL() e?GzvM'2  
{ ^>fr+3a"P  
return sSiteURL; x%dVD  
} eQfXUpk3@I  
T&<ee|t@{  
,RAP_I!_x  
public void setSSiteURL(String value) a]8W32  
{ w`/~y   
sSiteURL = value; szOa yAS  
} J0t_wM Ja  
*~UK5Brf1  
z4]z3U<}3]  
public String getSFilePath() AZ\f6r{  
{ J'wJe,  
return sFilePath; $9 G".T  
} d]?fL&jr  
0yb9R/3.  
zTn.#-7y  
public void setSFilePath(String value) --vJR/-  
{ +5:9?&lH  
sFilePath = value; }JUc!cH8z  
} ,OkI0[  
GN+,9  
iqWkhJphv  
public String getSFileName() _Qb ].~  
{ lI9|"^n7F  
return sFileName; vcP_gJz  
} 7VLn$q]:  
+Q:)zE  
R0GD9  
public void setSFileName(String value) '^'PdB  
{ #A< |qd  
sFileName = value; LZJFp@  
} ,K.Wni#m  
&5%~Qw..  
+N|t:8qaf  
public int getNSplitter() ndvt $*  
{ AFsYP/g]  
return nSplitter; MJn=  
} %^u e  
^>y|{;`  
\rH0=~F-P  
public void setNSplitter(int nCount) aMxM3"  
{ ABq#I'H#@2  
nSplitter = nCount; :{-/b  
} uPb.uG  
} r;"Qu  
GCxmqoQ  
}AS3]Lub@  
/* Bv 7os3xb  
**Utility.java bhW&,"$Z  
*/ <^e  
package NetFox; +rDKx(Rk  
kr44@!s+'  
FJsM3|{2=d  
public class Utility { QghL=  
H 9?txNea  
Jg6@)<n  
public Utility() D@ BP<   
{ i\ )$  
b,#?LdQ%  
cfc=a  
} Ece=loV*l  
hz-^9U  
//线程睡眠 U@LIw6B!KL  
public static void sleep(int nSecond) iu`B8yI  
{ 87R$Y> V  
try{ =o[H2o y  
Thread.sleep(nSecond); {t('`z  
} oe=W}y_k  
catch(Exception e) suN}6C I  
{ uLt31G()  
e.printStackTrace (); -]:1zU  
} `I(5Aj"  
} l~x 6R~q  
E/C3t2@-  
//日志 \"+}-!wr  
public static void log(String sMsg) 8?hj}}H  
{ YG#{/;^nm)  
System.err.println(sMsg); Mw6 Mt  
} M1K[6V!   
=BeJ.8$@VC  
6PLdzZ{  
public static void log(int sMsg) Fw%S%*B8g  
{ e#ne5   
System.err.println(sMsg); 1 @q"rPE^  
} fs, >X!l+  
} !*,m=*[3  
 N1dM,H  
E$4Ik.k  
/* wqJ1^>TB  
**TestMethod.java i >BQRbU  
*/ p '=XW#2 >  
package NetFox; R1Q~UX]d=  
+ ;B K|([#  
F^cu!-L  
public class TestMethod { 41i#w;ojI  
OB+QVYk"  
J/c5)IB|  
public TestMethod() .R&jRtb/E  
{ ///xx/weblogic60b2_win.exe n-CFB:L  
try{ Z07SK ' U  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |bk$VT4\  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =qww|B92  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9y;zk$O8  
fileFetch.start(); jjg[v""3|  
} "X-"uIc  
catch(Exception e){e.printStackTrace ();} 4z^VwKH\j  
&C6*"JZ4  
S|_"~Nd=  
} c,5yH  
-D wO*f  
Ots]y  
public static void main(String[] args) S\6.vw!'  
{ 8q|T`ac+N  
new TestMethod(); +VO(6Jn  
} %}Z1KiRiX  
} |N5|B Q(y$  
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