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http断点续传简单实现(java)

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/* \[>Ob  
**SiteFileFetch.java @MoBR.  
*/ -lb,0   
package NetFox; 5}+&Em":  
import java.io.*; YLx4qE  
import java.net.*; lWR".  
|+aUy^  
RCL}bE  
public class SiteFileFetch extends Thread { -](NMRqfN  
C'wRF90  
Sb/`a~q ^  
SiteInfoBean siteInfoBean = null; //文件信息Bean M zRliH8e  
long[] nStartPos; //开始位置 `hVi!Q]*P  
long[] nEndPos; //结束位置 w|k?2 ?&  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ~fht [S?@M  
long nFileLength; //文件长度 x}tg/` .=z  
boolean bFirst = true; //是否第一次取文件 ~OE1Sd:2  
boolean bStop = false; //停止标志 4eRV?tE9  
File tmpFile; //文件下载的临时信息 2m*g,J?ql  
DataOutputStream output; //输出到文件的输出流 (\I9eBm  
&tJ!cTA.-  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) j@Ta\a-,x  
public SiteFileFetch(SiteInfoBean bean) throws IOException VqIzDs  
{ P4VMGP  
siteInfoBean = bean; XHh!Q0v;  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); eXYf"hU,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); !bq3c(d  
if(tmpFile.exists ()) Qms,kX  
{ QMz6syn4u  
bFirst = false; M SnRx*-  
read_nPos(); g0Ff$-#7  
} wAvnj  
else *6` };ASK  
{ ^E#i5d+'N  
nStartPos = new long[bean.getNSplitter()]; . XVW2ISv  
nEndPos = new long[bean.getNSplitter()]; it#,5#Y:  
} ,u<oAI`  
gB)Cmw*  
k vQ] }`a  
PsMp &~^  
} 0D s W1  
jR_o!n~5  
#$^vP/"$  
public void run() Qf .ASC   
{ yU{Q`6u T  
//获得文件长度 <NYf!bx  
//分割文件 0DB8[#i%:  
//实例FileSplitterFetch "G[yV>pxv  
//启动FileSplitterFetch线程 [Nw%fuB  
//等待子线程返回 ]Uu:t  
try{ 9sI&&Jg  
if(bFirst) b)(rlX  
{ d$gT,+|vu  
nFileLength = getFileSize(); j`o_Stbg  
if(nFileLength == -1) <Crbc$!OeX  
{ F*, e,s  
System.err.println("File Length is not known!"); |nMg.t`8  
} yP^C)  
else if(nFileLength == -2) Pe,:FIp,  
{ 0|=,!sY  
System.err.println("File is not access!"); `mE>h4  
} K-2oSS56  
else DfsPg':z  
{ QSNPraT  
for(int i=0;i<nStartPos.length;i++) QE Q/  
{ `Q!#v{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Oj,v88=  
} Q&@e,7]V+  
for(int i=0;i<nEndPos.length-1;i++) zAkF:^#Y  
{ O}3|UI!`  
nEndPos = nStartPos[i+1]; !SPu9:  
} B'D\l\w  
nEndPos[nEndPos.length-1] = nFileLength; Gv+$7{  
} ;xQNa}"V  
} >>b <)?3Rv  
c.eUlr_ {  
z4iTf8  
//启动子线程 5kx-s6 `!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !x$6wzKa  
for(int i=0;i<nStartPos.length;i++) MfU0*nVF~  
{ ]I[\Io1  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H 2JKQm_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [q!/YL3 %  
nStartPos,nEndPos,i); Gpf9uj%  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {~"fq.h!M  
fileSplitterFetch.start(); Q`m9I  
} xa[)fk$6  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _C54l  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !Pc&Sg  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }`uFLBG3  
nEndPos = " + nFileLength); fW z=bJ"V  
// fileSplitterFetch[nPos.length-1].start(); eq6>C7.$  
VxAG= E  
V]5MIiNl  
//等待子线程结束 oiTSpd-  
//int count = 0; h3rVa6cxM  
//是否结束while循环 QF4)@ r{2x  
boolean breakWhile = false; Aryp!oW  
?P%-p  
% 4Gt^:J"  
while(!bStop) d^+0=_[PmK  
{ Mpx98xcO  
write_nPos(); Kn*LwWne  
Utility.sleep(500); PSHzB! H=n  
breakWhile = true; <f9a%`d  
[C`LKA$t  
<]f{X<ef  
for(int i=0;i<nStartPos.length;i++) cw/E?0MWb  
{ v83@J~  
if(!fileSplitterFetch.bDownOver)  Eyq4w  
{ X6Q\NJ"B  
breakWhile = false; H{4_,2h =m  
break; :SD#>eD0  
} "DC L Z  
} g-4j1yJV<  
if(breakWhile) }B ?_>0  
break; M)"'Q6ck=  
@gnLY  
u\q(v D.  
//count++; O~#A )d6  
//if(count>4) 'm TQ=1  
// siteStop(); _-|+k  
} vyvb-oz;u  
L]* 5cH  
D4O^5?F)|  
System.err.println("文件下载结束!"); )8`i%2i=  
} v|R#[vtFd  
catch(Exception e){e.printStackTrace ();} 8bdx$,$k  
} Gzc`5n{"  
V<ii  
s=>^ 8[0O  
//获得文件长度 "BZL*hHq  
public long getFileSize()  OK(xG3T  
{ ~X(2F#{<{  
int nFileLength = -1; AD~_n ^  
try{ B8~bx%)3T  
URL url = new URL(siteInfoBean.getSSiteURL()); zyB>peAp6j  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4YgO1}%G  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~wQ M ?h  
'Ll'8 ps  
~7w LnB  
int responseCode=httpConnection.getResponseCode(); wlFK#iK  
if(responseCode>=400) FA{'Ki`  
{ ;]l`Q,*OXb  
processErrorCode(responseCode); =wMq!mBd  
return -2; //-2 represent access is error uhU'm@JZ  
} H6hhU'Kxf8  
9\VV++}s>o  
>mj WC) U  
String sHeader; d*dPi^JjC  
vDIsawbHD  
QIfP%,LT  
for(int i=1;;i++) 48_( 'z*>  
{ hd W7Qck"  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?-'GbOr!  
//Utility.log(in.readLine()); <m,bP c :R  
sHeader=httpConnection.getHeaderFieldKey(i); N%S|Ey@f   
if(sHeader!=null) bPIo9clq  
{ 9 ^=kt 2[  
if(sHeader.equals("Content-Length")) 8Oa+,?<0x  
{ (6i4N2  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?u5jX J0L  
break; u%5 ,U-  
} \A6 }=  
} ?e\u_3- 9  
else A{Qo}F<*  
break; a- lF}P\  
} OQVo4yl"  
} IEe;ygL#  
catch(IOException e){e.printStackTrace ();} MaLH2?je^n  
catch(Exception e){e.printStackTrace ();} 'Hsd7Dpi}  
TQykXZ2Yb)  
0J6* U[  
Utility.log(nFileLength); ?:6w6GwAA  
Bkg./iP5x  
N|%X/UjZ2.  
return nFileLength;  `7oYXk  
} <Ira~N  
Z&n#*rQ7[  
|Y v,zEY)  
//保存下载信息(文件指针位置) 3 bT?4  
private void write_nPos() V`rxjv}!  
{ [ OS& eK 8  
try{ T%A"E,#  
output = new DataOutputStream(new FileOutputStream(tmpFile)); eH~T PH  
output.writeInt(nStartPos.length); o7^0Lo5Z?  
for(int i=0;i<nStartPos.length;i++) lQv (5hIm  
{ c9djBUAk&  
// output.writeLong(nPos); fNV-_^,R9  
output.writeLong(fileSplitterFetch.nStartPos); *;l[|  
output.writeLong(fileSplitterFetch.nEndPos); )2 b-3lz  
} \}AJ)v*<  
output.close(); $wbIe"|  
} R 5\|pC  
catch(IOException e){e.printStackTrace ();} -wVuM.n(Z  
catch(Exception e){e.printStackTrace ();} eh8lPTKil  
} {{AZW   
hxt;sQAo{  
q3`~uTzk  
//读取保存的下载信息(文件指针位置) 8T8]gM  
private void read_nPos() `NNP}O2  
{ 4ves|pLET  
try{ j=c< Lo`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $W9dUR0  
int nCount = input.readInt(); a*t>Ks'C  
nStartPos = new long[nCount]; ZiRCiQ/?  
nEndPos = new long[nCount]; k"6v& O  
for(int i=0;i<nStartPos.length;i++) ?J-D6;  
{ 03_M+lv  
nStartPos = input.readLong(); AW'$5 NF>  
nEndPos = input.readLong(); wYDdy gS  
} )@<HG$#  
input.close(); ?X Rl\V  
} !}sF#  
catch(IOException e){e.printStackTrace ();} Oc-ia)v1G  
catch(Exception e){e.printStackTrace ();} _:FD#5BZ1  
} E,fbIyX  
u>:j$@56  
+O)ZB$w4  
private void processErrorCode(int nErrorCode) +??pej]Rp  
{ { R/e1-;  
System.err.println("Error Code : " + nErrorCode); |XMWi/p  
} iBmvy 7S?  
B5+$ VQ  
9i D&y)$"  
//停止文件下载 D&pp <  
public void siteStop() 1tTY )Evf  
{ kh8 M=  
bStop = true; h>p,r\X  
for(int i=0;i<nStartPos.length;i++) k5 *Z@a  
fileSplitterFetch.splitterStop(); A|GsbRuy  
7%G&=8tq  
u$X =2u:P  
} I}m>t}QRI_  
} u68ic1  
//负责部分文件的抓取 c~}FYO$  
**FileSplitterFetch.java k=G c#SD5_  
*/ Cq3Au%7  
package NetFox; cQsSJBZ[v5  
]:m4~0^#-(  
vu&ny&=`  
import java.io.*; [^XD @  
import java.net.*; 5DO}&%.xt  
Vy^mEsQC+h  
@1U6sQ  
public class FileSplitterFetch extends Thread { [z6P]eC7  
:Zo^Uc:*w  
b< []z,  
String sURL; //File URL eR/X9<  
long nStartPos; //File Snippet Start Position P.(z)!]  
long nEndPos; //File Snippet End Position 0DN&HMI#  
int nThreadID; //Thread's ID AS0mM HJk  
boolean bDownOver = false; //Downing is over rB|4  
boolean bStop = false; //Stop identical jo<Gf 5  
FileAccessI fileAccessI = null; //File Access interface 6/vMK<Fz9  
!& >LLZ  
[E"3 ?p  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nFe  
{ yo$A0Ti!w  
this.sURL = sURL; -y[y.#o  
this.nStartPos = nStart; r"p"UW9og  
this.nEndPos = nEnd; vE)d0l"  
nThreadID = id; R/ x-$VJ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QUg<~q)Oq  
} Hl*#iUq  
lTFo#p_(  
Y&y<WN}Q  
public void run() 07:h4beT  
{ wRq f'  
while(nStartPos < nEndPos && !bStop) XhN?E-WywQ  
{ AgB$ w4  
r5+ MjR  
%o`Cp64`Q  
try{ #qJ6iA6{  
URL url = new URL(sURL); +vPCr&40  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =#wE*6T9  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ri}JM3\J  
String sProperty = "bytes="+nStartPos+"-"; ;!OME*?m<  
httpConnection.setRequestProperty("RANGE",sProperty); V#c=O}  
Utility.log(sProperty); ;<%d^   
PWyFys  
]eX(K5 A  
InputStream input = httpConnection.getInputStream(); rP/W,! 7:K  
//logResponseHead(httpConnection); H>"P]Y)oX  
wy:euKB~   
'b+ Tio  
byte[] b = new byte[1024]; `8TL*.9  
int nRead; E~8J<g E  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Eh[NKgYL  
{ u/wWD@,  
nStartPos += fileAccessI.write(b,0,nRead); ZW 5FL-I  
//if(nThreadID == 1) nE :Wl  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GkKoc v  
} FY]Et= p  
~dLe9-_9  
db3.X~Cn#s  
Utility.log("Thread " + nThreadID + " is over!"); 'lgS) m  
bDownOver = true; W;U<,g '  
//nPos = fileAccessI.write (b,0,nRead); N'|9rB2e  
} g%D.sc)69  
catch(Exception e){e.printStackTrace ();} 0 4oMgH>Vd  
} 5p/.( |b,  
} 5z" X>!?^  
^Nysx ~6  
s5X51#J#~  
//打印回应的头信息 En0hjXa  
public void logResponseHead(HttpURLConnection con) 0,iG9D 7  
{ ? :F Jc[J  
for(int i=1;;i++) Kn2W{*wD  
{ P%<MQg|k`  
String header=con.getHeaderFieldKey(i); Ac/LNqIs  
if(header!=null) 1z@ ncqe  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5o0H7k]  
Utility.log(header+" : "+con.getHeaderField(header)); 18y'#<X!  
else |voZ0U  
break; lO}I>yo}\  
} W=,]#Z+M;  
} QR$m i1Vv\  
0iz\<' p  
uFOYyrESc  
public void splitterStop() ={{q_G\WD  
{ 4=|oOIhgb  
bStop = true; yWi?2   
} $tK/3  
W@~a#~1O  
\JNWL yw  
} K{FBrh  
0X%#9s ~  
i^rHZmT  
/* 5[^Rf'wy  
**FileAccess.java BIT<J5>  
*//文件访问(定位,写)  x![ut  
package NetFox; 0rc'SEl  
import java.io.*; jfZ)  
_~!c%_  
\u6/nvZ]N  
public class FileAccessI implements Serializable{ 6{ pg^K  
;]2d%Qt  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nh6!h%  
RandomAccessFile oSavedFile; a3:1`c/~\  
long nPos; D5!I{hp"  
|(9l_e|  
Q*/jQC  
public FileAccessI() throws IOException 5"Y:^_8  
{ hP jL  
this("",0); ~e+pa|lO  
} EsLtC5]  
`L.nj6F  
Sqla+L*  
public FileAccessI(String sName,long nPos) throws IOException {%X[Snv  
{ M|7{ZE`Y  
oSavedFile = new RandomAccessFile(sName,"rw"); OL623jQX  
this.nPos = nPos; nB%[\LtZ?  
oSavedFile.seek(nPos); }]j#C  
} IZxr;\dq6  
\Pd>$Q  
7#9fcfL  
public synchronized int write(byte[] b,int nStart,int nLen) ~8[`(/hj  
{ j8ac8J,}c  
int n = -1; RNX>I,2sh  
try{ CbT ;#0  
oSavedFile.write(b,nStart,nLen); wd Di5-A4  
n = nLen; tj tN<y  
} &lB>G[t  
catch(IOException e) +)7h)uq  
{ x|3G}[=  
e.printStackTrace (); ^]$rh.7&  
} t;lK=m|  
4n2*2 yTg  
44UN*_qG  
return n; n5?7iU&JIo  
} prVqV-S6TY  
;oRgg'k<  
ABhQ7 x|  
} p1,.f&(f  
IVG77+O# }  
7*47mJyc  
/* }kk[lvhJ  
**SiteInfoBean.java N!13QI H  
*/ `W4Is~VVv  
package NetFox; l/bZE.GJ  
K)9f\1\  
V_T~5%9Fy  
public class SiteInfoBean { qWI8 >my11  
*BQy$dfE  
Aj@t*3  
private String sSiteURL; //Site's URL Qf|c^B  
private String sFilePath; //Saved File's Path e]smnf  
private String sFileName; //Saved File's Name *GM.2``e  
private int nSplitter; //Count of Splited Downloading File SCXtBZ`.G  
Q% J!  
<GoZ>  
public SiteInfoBean() .IORvP-M&  
{//nSplitter的缺省值为5 f_ > lz  
//default value of nSplitter is 5 c)17[9"  
this("","","",5); R9%"Kxm  
} `AhTER  
AJt4I W@  
iKgH :[j  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E^V4O l<  
{ NKRH>2,  
sSiteURL= sURL; $(pVE}J  
sFilePath = sPath; ~ "WN4  
sFileName = sName; ] U[4r9V  
this.nSplitter = nSpiltter; oo!JAv}~  
}zHG]k,j  
{OW.^UIq^  
} BE," lX  
2r#W#z%vS  
<VmEXJIk  
public String getSSiteURL() `qj24ehc  
{ c]/&xRd  
return sSiteURL; ?uqPye1fc  
} w0fFm"A|W  
O@,9a~Ghd  
Q E*`#r#e  
public void setSSiteURL(String value) K=;oZYNd  
{ uJL[m(G  
sSiteURL = value; Z~ DR,:  
} }&IOBYHVDo  
Uj> bWa`  
'E1m-kJz  
public String getSFilePath() a &tl@y1  
{ -l q,~`v  
return sFilePath; {us"=JJVN  
} Lz}mz-N  
N uq/y=  
wnbKUlb  
public void setSFilePath(String value) Ea?u5$>gY"  
{ i^&^eg'.5  
sFilePath = value; lag%} ^  
} 5U%a$.yr  
)zq sn  
Vw b6QIs  
public String getSFileName() /}RW~ax  
{ ( T2 \   
return sFileName; @# &y  
} C(5B/W6  
{~eVZVv  
%n>*jFC  
public void setSFileName(String value) @ykM98K  
{ I0C$  
sFileName = value; [V.#w|n  
} )nA fT0()0  
^Euqy,8}  
_9b;8%? Yf  
public int getNSplitter() :/FT>UCL  
{ OG}m+K&<  
return nSplitter; p*" H&xA@  
} tD\%SiTg=b  
%P-z3 0FHp  
|fg{Fpc  
public void setNSplitter(int nCount) uY Y{M`  
{ %v 1NDhaXz  
nSplitter = nCount; 53X5&Bwh  
} ^jZ4tH3K  
} SpiI9)gp  
RS[>7-9  
X\'+);Z  
/* Kq2,J&Ca3  
**Utility.java cAc>p-y%  
*/ N?krlR  
package NetFox; @F0+t;  
rP7f~"L  
@b"J FB|  
public class Utility { `f+l\'.s  
e`Vb.E)  
u.L{3gkT  
public Utility() zQ~8(E]Rf  
{ uP veAK}h  
V.Ki$0>  
%,[p[`NRYR  
} H8'_.2vwX  
D\i8WU  
//线程睡眠 DZ~qk+,I  
public static void sleep(int nSecond) V50FX }i  
{ LHJjPf)F  
try{ .l(t\BfE~  
Thread.sleep(nSecond); Ud[Zv?tA:  
} \w\{x0u  
catch(Exception e) a}MSA/K(  
{ WaYT7 :  
e.printStackTrace (); COk;z.Kn  
} 1Ydym2  
} 6`Af2Y_  
eW^_YG%(  
//日志 4` zfrT^  
public static void log(String sMsg) ;OynkZs)  
{ *%wfR7G[B  
System.err.println(sMsg); sM$gfFx  
} .,5N/p"aV  
a+Z95~*sZ"  
W_ hckq.  
public static void log(int sMsg) fd} U l  
{ |T@\ -8Ok  
System.err.println(sMsg); ^+20e3 ~Y  
} 1JXa/f+  
} 4tv}V:EO  
vPA {)l\K  
c3$h-M(jVJ  
/* =UW! 7OzC  
**TestMethod.java t^zmv PDK  
*/ dJ}E,rW}  
package NetFox; 5??\[C^"}  
9dFSppM  
| p"E0av  
public class TestMethod { ` kG}NJf  
J` J^C  
kt*""&R  
public TestMethod() _H+|Ic  
{ ///xx/weblogic60b2_win.exe 5VG[FY6Pl  
try{ g-Y2U}&  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CZL:&~l1  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v2uyn  
SiteFileFetch fileFetch = new SiteFileFetch(bean); g:sn/Zug]  
fileFetch.start(); 6*n<emP  
} SuU_psF  
catch(Exception e){e.printStackTrace ();} z rg#BXj7  
_b8?_Zq  
8I`t`C/4  
} \Gk4J<  
a*Oc:$  
r)G^V&96  
public static void main(String[] args) tgPx!5U  
{ Rr|&~%#z  
new TestMethod(); {:;599l  
} wtY*{m2  
} D+ )R_  
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