http断点续传简单实现（java)

/* 0e+#{k  
**SiteFileFetch.java S-}c_zbl;  
*/ ^>&#F[aT  
package NetFox; hJ]Oa7r  
import java.io.*; @"BhKUoV$K  
import java.net.*; M)!"R [V  
~Kt1%&3{a?  
/V{UTMSz  
public class SiteFileFetch extends Thread { Zj-U^6^L  
i-w$-2w  
-b{<VrZ  
SiteInfoBean siteInfoBean = null; //文件信息Bean zwU[!i)  
long[] nStartPos; //开始位置 [*5]NNB  
long[] nEndPos; //结束位置 ?}v/)hjp=?  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 pDYJLh-C  
long nFileLength; //文件长度 [U",yN]d  
boolean bFirst = true; //是否第一次取文件 343d`FRa}  
boolean bStop = false; //停止标志 DO*  
File tmpFile; //文件下载的临时信息 q^<H
G]  
DataOutputStream output; //输出到文件的输出流 j'U1lEZm2  
K
:jn^JN$  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） i!}6FBZ  
public SiteFileFetch(SiteInfoBean bean) throws IOException $[Z~BfSQ  
{ 2"?DaX  
siteInfoBean = bean; SepwMB4@  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); bEj}J_#  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); \?R#ZxP@  
if(tmpFile.exists ()) EnlAgL']|  
{ 14,t  
bFirst = false; U;WwEta ]  
read_nPos(); $/C1s"C@O  
} q`/J2r+O  
else W>i%sHH6  
{ ~tt\^:\3~S  
nStartPos = new long[bean.getNSplitter()]; .4R.$`z4  
nEndPos = new long[bean.getNSplitter()]; lya},_WCq  
} p&x!m}!  
~G@YA8}  
ha$1vi}b  
65dMv*{  
} NJ.oME@=  
d1\nMm}v  
qe#5;
#  
public void run() ,3 /o7'  
{ Sx QA*}N  
//获得文件长度 RG'76?z  
//分割文件 (m,H
 5  
//实例FileSplitterFetch *l{epum;  
//启动FileSplitterFetch线程 Nj3iZD|  
//等待子线程返回 u%e~a]  
try{ -W1p=od
 
if(bFirst) YLQ0UeDN'  
{ ws5Ue4g|  
nFileLength = getFileSize(); z9[TjTH^}T  
if(nFileLength == -1) WYTqQqQk  
{ qE[YZ(/f0&  
System.err.println("File Length is not known!"); vs=q<Uw)  
} "lw|EpQk`  
else if(nFileLength == -2) |&JeJ0k>~  
{ }}$@Tij19[  
System.err.println("File is not access!"); Znb7OF^#"  
} O#ZZ PJ"  
else QHZ",1F  
{ o zn&>k  
for(int i=0;i<nStartPos.length;i++) PjEJC@n  
{ 1J"9Y81  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); g assOd  
} 5[SwF&zZ  
for(int i=0;i<nEndPos.length-1;i++) SDil\x  
{ ebI2gEu;a  
nEndPos = nStartPos[i+1]; 8!Wh`n<  
} ').)0;  
nEndPos[nEndPos.length-1] = nFileLength; Rv9jLH  
} 9D1WUUa  
} 30uPDDvar  
 #O}}pF  
;\2Z?Kq  
//启动子线程 T9Q3I  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o=($'(1  
for(int i=0;i<nStartPos.length;i++) hA5')te<  
{ A\Ib  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H,L{N'[Xph  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +m%%Bz>  
nStartPos,nEndPos,i); Icrnu}pl_  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N7J?S~x  
fileSplitterFetch.start(); )xyjQ|b  
} %r(WS_%K|  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )e?&'wa>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lUs$I{2_  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j0mN4Ny  
nEndPos = " + nFileLength); Mz6(M,hkq  
// fileSplitterFetch[nPos.length-1].start(); 6EyPZ{  
ZK^cG'^2|  
&}k7iaO  
//等待子线程结束 &R<aRE:+R  
//int count = 0; @!f4>iUy  
//是否结束while循环 X n!mdR  
boolean breakWhile = false; O[ird`/  
- /\qGI  
+,>%Yb=EA  
while(!bStop) F,
p0OL.  
{ @h{|tP%"  
write_nPos(); W[O
]Aal{  
Utility.sleep(500); GmWr  
breakWhile = true; ?x #K:a?  
~< bpdI0  
H\ejW@<;h  
for(int i=0;i<nStartPos.length;i++) Yn
}Gj'  
{ Re8x!e'>  
if(!fileSplitterFetch.bDownOver) !Rl|o^Vw>{  
{ NAvR^"I~  
breakWhile = false; !|&|%x6@  
break; *tF~CG$r  
} 8mreHa  
} o2ggHZe/=@  
if(breakWhile) Bxm,?=h  
break; (CxA5u1|l  
:uo1QavO@,  
f*XCWr  
//count++; R}=5:)%w  
//if(count>4) ?ZRF]\dP]  
// siteStop(); p5fr}#en  
} eTx9fxw  
!lgL=Ys(  
JkAM:,^(  
System.err.println("文件下载结束！"); vAUt~X"  
} 13!@LbC  
catch(Exception e){e.printStackTrace ();} }~I!'J#)  
}  lln"c  
j HHWq>=d  
h4pS~/  
//获得文件长度 
|q77  
public long getFileSize() ~:z.Xu5m  
{ s7 "xDDV  
int nFileLength = -1; p,fV .5q  
try{ Wm}c-GD  
URL url = new URL(siteInfoBean.getSSiteURL()); K?^;|m-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'K,\
  
httpConnection.setRequestProperty("User-Agent","NetFox"); t_3j_`  
1(?4*v@B  
.zO2g8(VR  
int responseCode=httpConnection.getResponseCode(); c1'@_Is  
if(responseCode>=400) (gBKC]zvz3  
{ 8 c8`"i  
processErrorCode(responseCode);
N6y9'LGG`  
return -2; //-2 represent access is error %F>~2g?$  
} ii)#(b:V  
K|7"YNohfG  
Ht Fr(g\"$  
String sHeader; uDDa>Ka#+  
te+}j7SU  
R{#< NE  
for(int i=1;;i++) l$;"yVdks  
{ 9*)&hhBs,  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dEoIVy_9R  
//Utility.log(in.readLine());
\Z]+j@9  
sHeader=httpConnection.getHeaderFieldKey(i); X8|H5Y:  
if(sHeader!=null) pr0X7 #_E5  
{ ]nTeTW  
if(sHeader.equals("Content-Length")) <,]:jgX  
{ JtL>mH  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t}q e_c  
break; Js,!G  
} p27Dcwov  
} )O1
]|r7v  
else Xsq@E#@S  
break; 
*'/,  
} p/h\QG1   
} Y [`+7w  
catch(IOException e){e.printStackTrace ();} ?*fa5=ql  
catch(Exception e){e.printStackTrace ();} d9f7 &  
+K4XMf  
G$<(>"Yr~$  
Utility.log(nFileLength); 5p0~AN)  
a1cX+{W  
|`T(:ZKXZ2  
return nFileLength; CY1WT  
} ')uYI;h9  
&`D$w?beg  
U zy@\  
//保存下载信息（文件指针位置） Mg2+H+C~:  
private void write_nPos() ]&*POri&  
{ 9p{4-]  
try{  =z.j{%  
output = new DataOutputStream(new FileOutputStream(tmpFile)); G]K1X"W?  
output.writeInt(nStartPos.length); #I/P9)4  
for(int i=0;i<nStartPos.length;i++) oB:7R^a  
{ 1V%tev9a  
// output.writeLong(nPos); jRK}H*uem  
output.writeLong(fileSplitterFetch.nStartPos); Y6jyU1>  
output.writeLong(fileSplitterFetch.nEndPos); 6j%%CWU{~  
} %rW}x[M%w?  
output.close(); my'nDi  
} "<CM'R  
catch(IOException e){e.printStackTrace ();} }.&nEi`  
catch(Exception e){e.printStackTrace ();} ;2f=d_/x  
} n1-p/a.  
}je<^]a  
.p#kW:zspA  
//读取保存的下载信息（文件指针位置） ]*2),H1 c  
private void read_nPos() E)v~kC}7.  
{ noZbsI4  
try{ K.Xy:l*z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y)rK'OY'  
int nCount = input.readInt(); R3>q]  
nStartPos = new long[nCount]; Y 6a`{'  
nEndPos = new long[nCount]; MP%#)O6  
for(int i=0;i<nStartPos.length;i++) 'n &p5%  
{ RNT9M:w  
nStartPos = input.readLong(); ?WI v4
 
nEndPos = input.readLong(); ^{Y,`F  
} W5|{A])N  
input.close(); `Y&`2WZ ~  
} &[ })FI  
catch(IOException e){e.printStackTrace ();} >q}3#TvP@  
catch(Exception e){e.printStackTrace ();} )PYPlSQ*V  
} k[Em~>m  
'@n"'vks(\  
K; #FU  
private void processErrorCode(int nErrorCode) e{)giJY9  
{ odP<S.  
System.err.println("Error Code : " + nErrorCode); l)u%`Hcn  
} ]cRvdUGv  
zEQ]5>mG  
?^&ih:"  
//停止文件下载 Ac_P^  
public void siteStop() -laH^<jm5  
{ HhbBt'fH  
bStop = true; $(1t~u<17  
for(int i=0;i<nStartPos.length;i++) :5kDc" =Z|  
fileSplitterFetch.splitterStop(); !?,, ZD  
vl (``5{  
1g;2e##)  
} Kw fd S(
 
} }&v}S6T  
//负责部分文件的抓取 L$ T2 bul  
**FileSplitterFetch.java ,EQ0""G!  
*/ rZUTBLZ`j  
package NetFox; &9e  
4 ]oe`yx  
x?i wtZ@  
import java.io.*; %JeNDXbI4  
import java.net.*; m(f`=+lqI`  
frcAXh9  
bJ2-lU% ;2  
public class FileSplitterFetch extends Thread { ]OpGD5jZ  
cW3'057  
wSR|uh  
String sURL; //File URL 49FP&NgK  
long nStartPos; //File Snippet Start Position igu1s}F  
long nEndPos; //File Snippet End Position {4+/0\  
int nThreadID; //Thread's ID :!i=g+e]  
boolean bDownOver = false; //Downing is over tQ}GTqk  
boolean bStop = false; //Stop identical g~<[;6&{  
FileAccessI fileAccessI = null; //File Access interface 1d<?K7%^  
`^#Rwn#  
o[;P@F  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r\m{;Z#LJm  
{ 4"
?`p;{Z  
this.sURL = sURL; Lg\3DzM  
this.nStartPos = nStart; w
1<pQ[A  
this.nEndPos = nEnd; RE!WuLs0"  
nThreadID = id; +*.*bo  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )Kx.v'  
} 8GkWo8rPk  
AQ-PHv  
\>$zxC_  
public void run() pj%]t  
{ Zbo4{.#  
while(nStartPos < nEndPos && !bStop) ZK4V-?/[6  
{ 7(/yyZQnZ  
aZf/WiR2  
bK "I9T #  
try{ DY`0 `T  
URL url = new URL(sURL); 3]S*p ErY  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W[jg+|  
httpConnection.setRequestProperty("User-Agent","NetFox"); 0\i\G|5  
String sProperty = "bytes="+nStartPos+"-"; 6jpzyf=~  
httpConnection.setRequestProperty("RANGE",sProperty); +[}y` -t  
Utility.log(sProperty); u^Cls!C  
tMLiG4 |7  
g9C-!X-<T  
InputStream input = httpConnection.getInputStream(); -~z@W3\  
//logResponseHead(httpConnection); xxGm T.&  
x& _Y( bHA  
wPU5L*/*i  
byte[] b = new byte[1024]; kR+}7G+  
int nRead; !>(uhuTBF  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :V(C+bm *  
{ fBX@ MedC  
nStartPos += fileAccessI.write(b,0,nRead); %:
C6\4  
//if(nThreadID == 1) a;$V;3C{b&  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WX Fm'5Vr  
} W~H`{x%Av>  
1n8y4k)  
/J}G{Y |n  
Utility.log("Thread " + nThreadID + " is over!"); $2FU<w$5  
bDownOver = true; U*nB= =  
//nPos = fileAccessI.write (b,0,nRead); x)80:A}  
} "1|geO|  
catch(Exception e){e.printStackTrace ();} j&ti "|2\  
} &._"rhz  
} 39^+;Mev  
)EMlGM'2q  
`U0XvWPr[  
//打印回应的头信息 IV~)BW leT  
public void logResponseHead(HttpURLConnection con) C32*RNG?U  
{ f)vnm*&-  
for(int i=1;;i++) xS,F DPA  
{ #Q2s3"X[  
String header=con.getHeaderFieldKey(i); .LAB8bg  
if(header!=null) i:Y5aZc/Ds  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t7-r YY(  
Utility.log(header+" : "+con.getHeaderField(header)); ~_BjcY  
else ?uCL[  
break; fFEB#l!oUb  
} &CRgi488b  
} o0AT&<K  
+M.BMS2A<l  
86LE )z  
public void splitterStop() 5XT^K)'  
{ z81dm  
bStop = true; ~F@p}u8TV  
} bD)"Jy  
)fo0YpE^|  
HH6n3c!:mm  
} E$_zBD%  
'Rnzu0<lF  
a /]FlT  
/* aF/DFaiYv  
**FileAccess.java m|JA}&A  
*//文件访问(定位，写) @GXKqi  
package NetFox; 4SUzR\  
import java.io.*; T5`ML'Dej  
f0@*>  
UvMkL  
public class FileAccessI implements Serializable{ _zbIS&4  
,J2qLH1  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z}}P+P/  
RandomAccessFile oSavedFile; "+2
C
s  
long nPos; ,e|"p[z~T  
B0 A`@9  
7"Nd
a3  
public FileAccessI() throws IOException ^EN )}:%Z  
{ L~/L<Ms  
this("",0); `]]5!U2  
} =84EX<B  
l4mRNYv)z  
W*iTg%a\k  
public FileAccessI(String sName,long nPos) throws IOException ]Ndy12,M  
{ S~r75] "  
oSavedFile = new RandomAccessFile(sName,"rw"); |[r7
B*fw  
this.nPos = nPos; kE6/
d,
 
oSavedFile.seek(nPos); RU#}!Kq  
} &b>&XMIK  
iN[6}V6Sm  
K:9AP{+  
public synchronized int write(byte[] b,int nStart,int nLen)
ObZhQ.&  
{ RFsUb:%V7-  
int n = -1; x?A<X2  
try{ *Dq ++  
oSavedFile.write(b,nStart,nLen); Tei2[siA5  
n = nLen; q%M~gp1  
} W'Ew!]Q3  
catch(IOException e) bD/ZKvg  
{ #B <%  
e.printStackTrace (); tKyGD|g S  
} IlO,Ql  
6jm?d"9  
2aR9vmR  
return n; A ?tna6W:  
} *BrGh
 
izcjI.3e,  
[QMN0#(h  
} @x*xgf  
AMB{Fssz  
sWse (_2  
/*  mVS^HQ:  
**SiteInfoBean.java Hr=|xw8.  
*/ k:V9_EI=  
package NetFox; hl0X,G+@  
mw^>dv?  
uDJ;GD[yc  
public class SiteInfoBean { ;:oXe*d  
&'zc2  
t%e<]2-8  
private String sSiteURL; //Site's URL ]Hl{(v\HO  
private String sFilePath; //Saved File's Path QoUdTIIL  
private String sFileName; //Saved File's Name _R]0S  
private int nSplitter; //Count of Splited Downloading File }M(xN6E  
 %nUN  
H}_R`S  
public SiteInfoBean() z}==6|{  
{//nSplitter的缺省值为5 aso8,mpZuA  
//default value of nSplitter is 5 nVoWER:  
this("","","",5); _pb*kJ  
} "uL~D5!f  
9fs-|E[5  
Vp1ct06^  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a6xo U;T  
{ C6F7,v62  
sSiteURL= sURL; Odw'Ua  
sFilePath = sPath; Wj!+ E{y<r  
sFileName = sName; *pD|N  
this.nSplitter = nSpiltter; $8(QBZq  
a_0I)' ?  

WB_BEh[>j  
} OXpN8Dh5  
fD(r/~Vu  
x%k@&d;z  
public String getSSiteURL() PRUl-v  
{ rqp]{?33  
return sSiteURL; p-\->_9)y`  
} D/"velV  
5|r*,!CF  
21Dc.t{  
public void setSSiteURL(String value) <@GO]vY  
{ 2
?6]Xbs{  
sSiteURL = value; xR kw+  
} j `!Ge  
nhMxw@Z\  
xDl; tFI  
public String getSFilePath() &uc`w{,Zs  
{ dG0zA D  
return sFilePath; Id`V`|q  
} Nr]Fh  
Sx J0Y8#z  
HnjA78%i  
public void setSFilePath(String value) djnES,^%9  
{ MCEHv}W  
sFilePath = value; =#pYd~  
} PCL ;Z  
9,JM$ Y {  
l(87s^_  
public String getSFileName() ?aWVfX!+G5  
{ EFx>Hu/[G  
return sFileName; 'nM4t  
} Ye$j43b  
sCt)Yp+8}B  
<FU?^
*~  
public void setSFileName(String value) o9sPyY$aQ  
{ R ai 04  
sFileName = value; +C~d;p  
} (p12=EB<  
G{4s~Pco[Q  
ilK*Xo  
public int getNSplitter() g=t7YQq_~  
{ ^dk$6%0  
return nSplitter; u_+iH$zA
 
} vOz1& |;D  
-8FUR~WJ  
Nb9GrYIS  
public void setNSplitter(int nCount) >"=DN5w ,S  
{ |LbAW/9a  
nSplitter = nCount; vC@^B)
5gb  
} iKd+AzT  
} N8Zz6{rp  
Mh~}RA"H  
F xm:m  
/* ?$)5NQB%  
**Utility.java RzL(Gnb  
*/ a,S;JF)v  
package NetFox; <>{m+=gA  
MYjc6@=cR  
ojlyW})$%  
public class Utility { *-5N0K<kQ  
Q0K$ZWM`7  
.?QYqGcG  
public Utility() dTK0lgkUE  
{ $fg@g7_:  
K
.mxF,H  
yj_>G  
} 6*>Lud  
@j}%{Km]Y  
//线程睡眠 m#8PX$_  
public static void sleep(int nSecond) ]7K2S{/o{  
{ 7`A]X,:  
try{ RQo a  
Thread.sleep(nSecond); I-r+1gty  
} wz69Yw7  
catch(Exception e) :zKMw=  
{ VSDua.  
e.printStackTrace (); /<8y>  
} X)~wB7_0G  
} 4RtAwB  
7LrmI~P  
//日志 b\`S[  
public static void log(String sMsg) `a MU2  
{ 9>9EZ?4m  
System.err.println(sMsg); fM"*;LN!N  
} =s4(Y  
Lm2!<<<  
A|+QUPD  
public static void log(int sMsg) /IRXk[  
{ KB](W  
System.err.println(sMsg); [C0v-  
} 7LVG0A2>7  
} <OGG(dI  
If,p!L  
Q7XOO3<):  
/* I@9'd$YY  
**TestMethod.java Is7BJf  
*/ w90YlWS#  
package NetFox; J>}J~[ap\J  
\/Mx|7<  
^ UmYW  
public class TestMethod { z.SC^/\o|  
bqAW  
[#q>Aq$11  
public TestMethod() *|dr-e_j  
{ ///xx/weblogic60b2_win.exe }
Rw,4  
try{ kzRJzJquP  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [rT.k5_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [|KvlOvP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); P$z_A8}  
fileFetch.start(); 1Q>nS[  
} |sReHt2)d  
catch(Exception e){e.printStackTrace ();} ;cI*"-I:F  
\4>,L_O  
m<-ShRr*b  
} I} jgz  
3@gsKtA&H4  
V|_ h[hXE  
public static void main(String[] args) O[C4xq  
{ ^E.L8  
new TestMethod(); 1Hr}n6s  
} 22CET9iCe  
} kJ_8|  
点击下载更多相关资料