http断点续传简单实现（java)

/* StWDNAf
)  
**SiteFileFetch.java MC/$:PV  
*/ sMli!u  
package NetFox; #$%9XD3  
import java.io.*; .9> er  
import java.net.*; YL&$cT]1  
;)[RG\  
bvn?wK  
public class SiteFileFetch extends Thread { B8 -/C\  
V;?_l?_  

|hehROUn  
SiteInfoBean siteInfoBean = null; //文件信息Bean "OF
YVK\]i  
long[] nStartPos; //开始位置
C^Tc9  
long[] nEndPos; //结束位置 \SnW(,`oX  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 kR6rf
_-[  
long nFileLength; //文件长度 88h-.\%Z  
boolean bFirst = true; //是否第一次取文件 JiP]FJ;  
boolean bStop = false; //停止标志 &6,GX7]Fo  
File tmpFile; //文件下载的临时信息 *%'4.He7V  
DataOutputStream output; //输出到文件的输出流 #O^H?3Q3  
[X)+(-J  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） jDcE_55o  
public SiteFileFetch(SiteInfoBean bean) throws IOException ;=hl!CB  
{ b]~X U  
siteInfoBean = bean; wCe
Ss=[  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5?k_Q"~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ~*Ve>4  
if(tmpFile.exists ()) HGB96,o f9  
{ 4XQv  
bFirst = false; M9]O!{sq  
read_nPos(); gGN[AqR  
} 9#/z[!  
else J @"wJEF  
{ d7^:z%Eb|  
nStartPos = new long[bean.getNSplitter()]; W+a>*#*  
nEndPos = new long[bean.getNSplitter()]; q NU\XO`H  
} wsP3hE' ]  
BkA>':bUr  
y ']>J+b0  
wlC_rRj~  
} qDhz|a#  
1;SW%\M  
*f.eyg#  
public void run() M\,0<{  
{ &pK1S>t  
//获得文件长度 <X j:c2@  
//分割文件 WDY,?  
//实例FileSplitterFetch x+nrdW+  
//启动FileSplitterFetch线程 Lh"Je-x<<  
//等待子线程返回 @= 6}w_  
try{ O\XN/R3  
if(bFirst) ,y,NVF  
{ i+Px &9o<9  
nFileLength = getFileSize(); h -+vM9j  
if(nFileLength == -1) !zvKl;yT  
{ ;_of'  
System.err.println("File Length is not known!"); waQNX7Xdn  
} }Nl-3I.S^  
else if(nFileLength == -2) E92dSLhs5  
{ +kH*BhSj  
System.err.println("File is not access!"); ;QW6Tgt11  
} qUx!-DMY  
else f_9%kEXICt  
{ N|z-s  
for(int i=0;i<nStartPos.length;i++) odny{ePAf  
{ eek5Xm  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); rgB`<[:b  
} fa/ '4  
for(int i=0;i<nEndPos.length-1;i++) J@H9nw+Q  
{ D._q'v<  
nEndPos = nStartPos[i+1]; 9X@y*;w<t  
} zbx,qctYo$  
nEndPos[nEndPos.length-1] = nFileLength; ]Tf.KUm  
}  qeBfE  
} 7}%3Aw6]S  
^g~Asz5]  
w%VHq z$  
//启动子线程 %xyt4}-)m  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K4N~ApLB+  
for(int i=0;i<nStartPos.length;i++) 45edyQ  
{ oA"t`,3  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), st|$Fu  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E4HG`_cWb  
nStartPos,nEndPos,i); u\ytiGO*  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);
t=~al8  
fileSplitterFetch.start(); JQ%e'  
} V(=~p[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -/B}XNW  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CP|N
2rb  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lK9us  
nEndPos = " + nFileLength); 8K]fw{-$L  
// fileSplitterFetch[nPos.length-1].start(); ><TuL7+  
c|:H/Y2n|  
Od>Ta_  
//等待子线程结束 PD$ay^Y  
//int count = 0; V~&P<=8;Wl  
//是否结束while循环 aa.EtKl  
boolean breakWhile = false; S$%T0~PR~  
hp%|n:.G  
j S')!Wcu  
while(!bStop) Q68&CO(rE  
{
W~POS'1  
write_nPos(); 1V+a;-?  
Utility.sleep(500); +AtZltM i  
breakWhile = true; IW Lv$bPZ/  
f&js,NU"  
)2g\GRg6  
for(int i=0;i<nStartPos.length;i++) ^%)'wDK  
{ H-nk\ K<|  
if(!fileSplitterFetch.bDownOver) <)uUAh  
{ hc"+6xc  
breakWhile = false; 7cK#fh"hvg  
break; {Rc/Ten  
} &%>l9~F'~  
} s59
v* /  
if(breakWhile) z=N'evx~  
break; YnNB#x8|  
{e<J}-/?  
!Jh-v  
//count++; G>M# BuU  
//if(count>4) Vu*yEF}  
// siteStop(); &AU%3b  
} bguhx3s  
M9_ y>N[0  
a,#f%#J\  
System.err.println("文件下载结束！"); H(lq=M0~  
} ..Zuy|?w  
catch(Exception e){e.printStackTrace ();} bDeHU$  
} !Q*.Dw()[  
gkI(B2,/  
mSY;hJi  
//获得文件长度 g*N~r['dZ  
public long getFileSize() NC>rZS]  
{ % rRYT8  
int nFileLength = -1; m_W\jz??k  
try{ ipQJn_:2  
URL url = new URL(siteInfoBean.getSSiteURL()); wlAlIvIT  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j_L 'Ztu3  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?NGM<nK;7  
D}SRr,4v  
8ysU.5S  
int responseCode=httpConnection.getResponseCode(); Cj _Q9/  
if(responseCode>=400) ZK27^oG  
{ ua0`&,a3I  
processErrorCode(responseCode); WQ\'z?P  
return -2; //-2 represent access is error - A x$Y  
} SJ6lI66OX  
U8c0N<j  
_.' j'j%  
String sHeader; ?uc=(J+6  
hvtg_w6K  
E&Pv:h,pV&  
for(int i=1;;i++) 1/jJ;}  
{ al F*L  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G
LB7h9>  
//Utility.log(in.readLine()); N0O8to}V  
sHeader=httpConnection.getHeaderFieldKey(i); glH&v8  
if(sHeader!=null) $LRvPan`  
{ -w1U/o.  
if(sHeader.equals("Content-Length")) 0F8y8s  
{ V9`VFO  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kUUN2  
break; D(Pd?iQIO  
} MG*#-<OV.  
} (*;b\h  
else
we4e>)  
break; '\(Us^Ug  
} ` Xhj7%>  
} =<YG0K  
catch(IOException e){e.printStackTrace ();} }y(1mzb  
catch(Exception e){e.printStackTrace ();} ~k/'_1)c  
_VMW-trG
 
zy(sekX;  
Utility.log(nFileLength); !e?=I  
"A~\$  
5n"b$hMF  
return nFileLength; 8
9v9BWF  
} e4b`C>>  
6H+gFXIv  
v,bes[Ik  
//保存下载信息（文件指针位置） [M65T@v  
private void write_nPos() `{c %d  
{ =5l7{i*`  
try{ btkD<1{g  
output = new DataOutputStream(new FileOutputStream(tmpFile)); E y1mlW  
output.writeInt(nStartPos.length); = 7d{lK  
for(int i=0;i<nStartPos.length;i++) "a6[Fq
Ts  
{ ^GQ+,0Yy  
// output.writeLong(nPos); BD&JbH!(  
output.writeLong(fileSplitterFetch.nStartPos); |>5NH'agV  
output.writeLong(fileSplitterFetch.nEndPos); )'?3%$EM  
} G#t!{Q}8  
output.close(); &#;vR0O  
} oS 7q#`  
catch(IOException e){e.printStackTrace ();} 0j %s H  
catch(Exception e){e.printStackTrace ();} dZFf/BXU  
} qZ
'&zB)  
EdlU}LU  
#K.OJJaG  
//读取保存的下载信息（文件指针位置） 12U1DEd>-  
private void read_nPos() )s5Q4m!  
{ mY*JNx  
try{
X!ZUR^  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %D< =6suW  
int nCount = input.readInt(); )cJ9YKKy  
nStartPos = new long[nCount]; zlco?Rt  
nEndPos = new long[nCount]; u27K 0}  
for(int i=0;i<nStartPos.length;i++) Qh<_/X?  
{ w6zB uW  
nStartPos = input.readLong(); /oKa?iT  
nEndPos = input.readLong(); |k1(|)%G  
} #!wu}nDu  
input.close(); qPDe;$J)  
} ~2+J]8@I]  
catch(IOException e){e.printStackTrace ();} {U?/u93~  
catch(Exception e){e.printStackTrace ();} JWoNP/v6  
} b
W\OKI1  
as=Z_a:0N  
0"o%=i;  
private void processErrorCode(int nErrorCode) w[}5qAI5*f  
{ tGDsZ;3Yr  
System.err.println("Error Code : " + nErrorCode); LG0+A}E=C  
} )ZC0/>R  
.;&c<c|  
FpN>T  
//停止文件下载 ;|*o^9q  
public void siteStop() F`IV9qv  
{
}K1v=k  
bStop = true; ad+@2-Y  
for(int i=0;i<nStartPos.length;i++) U2m86@E  
fileSplitterFetch.splitterStop(); m>B^w)&C  
hg
[ob+"  
o9&1Ct  
} hC2@Gq  
} m%hI@'  
//负责部分文件的抓取 d#xi_L!  
**FileSplitterFetch.java 8MqKS}\H  
*/ zO)A_s.6K  
package NetFox; n`gW&5,,z  
Mhp6,JL  
3]"RaI4Q0  
import java.io.*; V<:scLm#OF  
import java.net.*; *;@V5[^3I?  
+NWhvs  
k|Mj|pqA  
public class FileSplitterFetch extends Thread { RG[b+Qjn  
qp$Td<'Y  
u}Kc
>/AF  
String sURL; //File URL #~QkS_  
long nStartPos; //File Snippet Start Position S bI7<_  
long nEndPos; //File Snippet End Position E>>@X^ =  
int nThreadID; //Thread's ID LgFF+z  
boolean bDownOver = false; //Downing is over M9so3L<N0  
boolean bStop = false; //Stop identical $fZVh%  
FileAccessI fileAccessI = null; //File Access interface ;|7]%Z}%  
3H"bivK
 
Iow45R~]  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U0>Uqk",  
{ K;j}qJvsb  
this.sURL = sURL; f/+UD-@%m  
this.nStartPos = nStart; OwRH :l  
this.nEndPos = nEnd; W Cz+  
nThreadID = id; ip.aM#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vU|=" #  
} |hGi8  
4:m/w!q$  
d0ZbusHHb  
public void run() QE8;Jk-  
{ )2
vkaR  
while(nStartPos < nEndPos && !bStop) 2smQD8t  
{ k6.<zs0  
BO]}E:C9  
e+416 ~X v  
try{ X'[93 C|K  
URL url = new URL(sURL); sX_6qKUH  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3s25Rps  
httpConnection.setRequestProperty("User-Agent","NetFox"); JSO'. [N  
String sProperty = "bytes="+nStartPos+"-"; w K)/m`{g  
httpConnection.setRequestProperty("RANGE",sProperty); `wrN$&  
Utility.log(sProperty); +2Xq+P  
wP-BaB$_  
Y243mq-  
InputStream input = httpConnection.getInputStream(); {jVEstP  
//logResponseHead(httpConnection); j\SvfZ0"  
\ct7~!qM  
;F3#AO4(  
byte[] b = new byte[1024]; XQW9/AzNf  
int nRead; _}G1/`09#  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /D@(o`a  
{ N5m+r.<;  
nStartPos += fileAccessI.write(b,0,nRead); x,LQA0  
//if(nThreadID == 1) 0=g~ozEW&  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 67,@*cK3?J  
} [&_c.ti  
#ArMX3^+w7  
(c3%rM m]  
Utility.log("Thread " + nThreadID + " is over!"); >U4hsr05  
bDownOver = true; &v}c3wL]  
//nPos = fileAccessI.write (b,0,nRead); q2>dPI;3T  
} Dq$co1eT  
catch(Exception e){e.printStackTrace ();} R>|)-"b( `  
} y*6-
?@  
}
s}m.r5  
1UyQ``v/  
QVEGd"WvvO  
//打印回应的头信息 (}^Qo^Vr  
public void logResponseHead(HttpURLConnection con) @-d0~.S  
{ )$Tcip`  
for(int i=1;;i++) IgxZ_2hO  
{ (A<'{J#5,  
String header=con.getHeaderFieldKey(i); (bT3 r_  
if(header!=null) ;_]Z3  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2p6`@8*34  
Utility.log(header+" : "+con.getHeaderField(header)); ^TWMYF-  
else )cF1?2  
break; 7"|j.Yq$H{  
} J|Af`HJ  
} =A yDVWpE  
vH`m W`=  
aM2[<m}  
public void splitterStop() *Y!c6eA  
{ 9bE/7v  
bStop = true; }iu
(-{Z  
} 97XGJ1HI  
Z3j
tq-y  
3B+ F'k&#  
} Tw)"#Y!T  
S zqY@  
BkO)hze  
/* C{"uz_Gh  
**FileAccess.java +|SvJ  
*//文件访问(定位，写) Po+tk5}''5  
package NetFox; c<T'_93  
import java.io.*; VlLc[eVV  
d7O\p(M1  
oJ<Wh @  
public class FileAccessI implements Serializable{ fD>0  
_mi(:s(  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xfq]vQ/{  
RandomAccessFile oSavedFile; $ 2/T]  
long nPos; BAQ;.N4  
4t Z. T9d  
@qGg=)T  
public FileAccessI() throws IOException vWM'}(  
{ [+j39d.Q  
this("",0); pbM"tr_A{  
} s3., N|  
 `LWZ!Q  
e.Y*=P}D  
public FileAccessI(String sName,long nPos) throws IOException nV$ctdusQ  
{ rwRb _eIj  
oSavedFile = new RandomAccessFile(sName,"rw"); fUJ\W"qya  
this.nPos = nPos; p]7Gj&a  
oSavedFile.seek(nPos); ;4g_~fB  
} #9F
e,  
TLkJZ4}?Q  
/
p&)bL  
public synchronized int write(byte[] b,int nStart,int nLen) @|2}*_3\  
{ (ex^=fv  
int n = -1; GA8cA)]zOD  
try{ Ul EP;  
oSavedFile.write(b,nStart,nLen); k*;2QED  
n = nLen; [H3~b=  
} Q I.
*6-(  
catch(IOException e) ,;_D~7L  
{ jE&Onzc  
e.printStackTrace (); -6()$cl}0  
} E?& x5?  
bhFAt1h  
l5jW`cl1  
return n; v7l4g&  
} }PR^Dj.  
K%p*:P  
Gn ]%'lrg'  
} fGv`.T_d  
F[ Itq  
P'nby
F  
/* 9t$%Tc#Z  
**SiteInfoBean.java GW(-'V/  
*/ Q)l]TgvSe  
package NetFox; ^z[-pTY  
(5"BKu1t  
cZ" Ut  
public class SiteInfoBean { $j~oB:3n7  
_n3Jf<Y  
Oc]&1>M  
private String sSiteURL; //Site's URL l7]$Wc[  
private String sFilePath; //Saved File's Path z"eh.&T  
private String sFileName; //Saved File's Name ?gSk%]S/!  
private int nSplitter; //Count of Splited Downloading File 3,K*r"=  
F7(~v2|  
lRn6Zh  
public SiteInfoBean() J-W,^%  
{//nSplitter的缺省值为5 Y=gj{]4  
//default value of nSplitter is 5 [xXml On!  
this("","","",5); \w 6%J77  
} !(!BW9Zt+  
6]|NB&  
V.Ig
EE]  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,x+_/kqx  
{ r: _-Cj  
sSiteURL= sURL; cVZCBcKC?  
sFilePath = sPath; ZSuMQ32  
sFileName = sName; 3q:-98DT  
this.nSplitter = nSpiltter; NVnKgGlHgd  
/HNZwbh]uJ  
"9[K  
} Y/t:9Aau  
y*M
,&,$  
Q<L.!%vu}  
public String getSSiteURL() ,EgIH%*g  
{ {-rK:*yP'u  
return sSiteURL; ];P^q`n=.  
} Ih}I`wY-  
K/~+bq#+  
Zq|oj^  
public void setSSiteURL(String value) yaf&SR@7k{  
{ u.gh04{5  
sSiteURL = value; *JG?^G"l  
} 6e@ O88=  
AJrwl^lm  
cU25]V^{\  
public String getSFilePath() 5 TD"  
{ lLHHuQpuj  
return sFilePath; S^
?OKqS  
} 1K'0ajl1A  
%PG::b  
y(:hN)  
public void setSFilePath(String value) sBIqee'T  
{ 0EM`,?i .Q  
sFilePath = value; <69/ZI),Y{  
} /KEPPp  
Tk-PCra  
u[U~`*i*rA  
public String getSFileName() do{#y*B/g!  
{ nzDS  
return sFileName; xZ@H{):  
} b?oT|@  
\n850PS  
@A6\v+ih  
public void setSFileName(String value) (Jfi 3 m  
{ v&(X&q  
sFileName = value; 9`^VuC'  
} ?B %y)K  
8\8uXOS  
gQ h0-Dnw  
public int getNSplitter() ]Bs ?  
{ L6j 5pI  
return nSplitter; $*%Ml+H-  
} uLb- NxQ-  
@Qx|!%  
d@"eWvnlZ  
public void setNSplitter(int nCount) -!MDYj+U  
{ w2~(/RgO  
nSplitter = nCount; o lNL|WJ`w  
} `hS<F" j  
} %H-[u}s  
*|Re,cY  
~0fT*lp  
/* AEi@t0By  
**Utility.java 3W
J> T1we  
*/ v?<x"XKR  
package NetFox; ##u+[ !  
q yy.3-(  
7F`QN18>(  
public class Utility { 7&klX  
AnPm5i.  
/[[zAq{OA  
public Utility() N)RWC7th{  
{ 9Pd~  
%@Ks<"9  
fB"3R-H?O  
} S#+G?I3w  
d"XS;;l%<  
//线程睡眠 5]; 8
 
public static void sleep(int nSecond) ;k7` `  
{ 5G){7]P+r"  
try{ *^c4q|G.-  
Thread.sleep(nSecond); v!@/  
} ItKwB+my  
catch(Exception e) 1elcP`N1  
{ 2O9dU 5b  
e.printStackTrace (); R^](X*  
} )gR14a  
} M)EKS  
=Mn!
[  
//日志 uh#PZ xnP  
public static void log(String sMsg) P>pkLP} Vo  
{ NfR,m]  
System.err.println(sMsg); 8+gx?pb  
} 'xStA  
7!oqn'#>A  
.1I];Cy0D  
public static void log(int sMsg) r'&9'rir2  
{ 9aZ3W<N`M  
System.err.println(sMsg); kc8GnKM&mc  
} 6{azzk8  
} K^{`8E&A  
Yc?taL)  
,l; &Tb=k  
/* (GPJ=r  
**TestMethod.java %/etoK  
*/ |,dMF2ADc  
package NetFox; tt J,rM  
bHS2;K~  
K!I]/0L  
public class TestMethod { `yYgL@Zt  
dN |w;|M  
//ZB B,[@  
public TestMethod() GeHDc[7  
{ ///xx/weblogic60b2_win.exe >+vWtO2  
try{ ?]9uHrdsN}  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .
[1A  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U%k e5uwP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); `Q(ac| 0  
fileFetch.start(); Q^MB%L;D  
} c_ygwO3.Q  
catch(Exception e){e.printStackTrace ();} }lpcbm  
[po+a@ %  
kOdS^-  
} @z/]!n\~  
i6`8yw  
\|62E):i1  
public static void main(String[] args) zZ32K@  
{ t_]UseP$RF  
new TestMethod(); BLaXp0  
} P< WD_W  
} HENCQ_Wra  
点击下载更多相关资料