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http断点续传简单实现(java)

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/* J:ka@2>|  
**SiteFileFetch.java ~$j;@ 4  
*/ n|DMj[uT  
package NetFox; T9]0/>  
import java.io.*; x FM^-`7  
import java.net.*; k4u/v n`&r  
qP##C&+#q  
J65:MaS  
public class SiteFileFetch extends Thread { Yl"CIgt  
"zQ<)Q]U  
S-~)|7d.  
SiteInfoBean siteInfoBean = null; //文件信息Bean y^nT G  
long[] nStartPos; //开始位置 o:3(J}  
long[] nEndPos; //结束位置 vx ' ];  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 wqV"fZA\]  
long nFileLength; //文件长度 `VUJW]wGu  
boolean bFirst = true; //是否第一次取文件 2  @T~VRy  
boolean bStop = false; //停止标志 #G`K<%{?f  
File tmpFile; //文件下载的临时信息 5VQ-D`kE+  
DataOutputStream output; //输出到文件的输出流 H8dS]N~[Y  
:i0;jWc b  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) W+U0Y,N6  
public SiteFileFetch(SiteInfoBean bean) throws IOException }gt)cOaY  
{ birc&<  
siteInfoBean = bean; -U A &Zt  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); yJ0 %6],^g  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); B)L0hi  
if(tmpFile.exists ()) 'r\RN\PT  
{ Vky]In=  
bFirst = false; -Eq[J k  
read_nPos(); mEi(DW)(  
} Qy[S~D_  
else %xQ'i4`  
{ 2e-bt@0t  
nStartPos = new long[bean.getNSplitter()]; <%m1+%mA.  
nEndPos = new long[bean.getNSplitter()]; !7)#aXt&  
} ANM=:EtP  
/QVwZrch  
&nI>`Q'  
Qo^(r$BD  
} 3tJfh=r=1  
!~R<Il|B  
Gr/}&+S  
public void run() 2QAP$f0Ln  
{ =2=rPZw9  
//获得文件长度 yZgWFf.X  
//分割文件 EStui>ho  
//实例FileSplitterFetch CxJ3u  
//启动FileSplitterFetch线程 w{k^O7~  
//等待子线程返回 }S?"mg& V  
try{ Z[] 8X@IPe  
if(bFirst) / j%~#@  
{ TecMQ0 KD  
nFileLength = getFileSize(); *l"CIG'  
if(nFileLength == -1) zn&ZXFgN  
{ ePJ_O~c  
System.err.println("File Length is not known!"); GbZ~e I`,2  
} WcY_w`*L  
else if(nFileLength == -2) j|&D(]W/  
{  zy"k b  
System.err.println("File is not access!"); Xy!NBh7I  
} V.qH&FJ=l  
else ~I;x_0iY4  
{ P2aFn=f  
for(int i=0;i<nStartPos.length;i++) @n.n[zb\|  
{ cqJXZ.X C  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Aaq%'07ihW  
} I=<Qpd4  
for(int i=0;i<nEndPos.length-1;i++) i '*!c  
{ n^hkH1vY  
nEndPos = nStartPos[i+1]; >1Hv c7DP  
}  8 zlvzp  
nEndPos[nEndPos.length-1] = nFileLength; Z}>F V~4  
} _(8#  
} Yk?q\1  
B&B:P  
DQP!e6Of  
//启动子线程 W SxoGly  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; srAWet  
for(int i=0;i<nStartPos.length;i++) ~TS!5Wiv  
{ ITqAy1m@C  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y*\h?p[,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8IxIW0  
nStartPos,nEndPos,i); ~xsJML  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "JLE  
fileSplitterFetch.start(); <Lxp t  
} w{xa@Q]t-  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oe|;>0yf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jIrfJ*z  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $':5uU1}  
nEndPos = " + nFileLength); T|D^kL%m!  
// fileSplitterFetch[nPos.length-1].start(); ty"L&$bf  
Z4As'al  
rEC  
//等待子线程结束 00dY?d{[D  
//int count = 0; ]cS(2hP7  
//是否结束while循环 4;AQ12<[1  
boolean breakWhile = false; O< /b]<[  
kBrA ?   
h^Yh~84T  
while(!bStop) se2Y:v  
{ {6RA~  
write_nPos(); _a& Z$2O  
Utility.sleep(500); *n&Sd~Mg  
breakWhile = true; PI`Y%!P  
|gu@b~8  
_b-g^#L%  
for(int i=0;i<nStartPos.length;i++) W'"?5} (  
{ )uo".n|n~B  
if(!fileSplitterFetch.bDownOver) (}>)X]  
{ x4wTQ$*1  
breakWhile = false; wEX<[#a-  
break; o -)[{o\  
} %$Py@g  
} G!I5Er0pdy  
if(breakWhile) G7+{O7  
break; z;?jKE p  
=>3,]hnep  
gzSm=6Qw0  
//count++; +6jGU '}[  
//if(count>4) p!=8Pq.  
// siteStop(); t1mG]  
} tx9 %.)M:n  
tKLeq(  
HpIi-Es7C  
System.err.println("文件下载结束!"); ILH[q>  
} 8N9,HNBT$  
catch(Exception e){e.printStackTrace ();} mk!8>XvM  
} w42{)S"  
0n`Temb/  
sH2xkUp  
//获得文件长度 Hf_ pe  
public long getFileSize() sn^ 3xAF  
{ 85[ 7lO)[  
int nFileLength = -1; ~Y*.cGA  
try{ Ank_;jo  
URL url = new URL(siteInfoBean.getSSiteURL()); c7@/<*E+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kv2o.q  
httpConnection.setRequestProperty("User-Agent","NetFox"); {fl[BX]kZ  
\I4Uj.'> \  
1D8S}=5&  
int responseCode=httpConnection.getResponseCode(); CPcUB4a%#  
if(responseCode>=400) %@)q=*=y  
{ ~'0n ]Fw  
processErrorCode(responseCode); }b}jw.2Wu  
return -2; //-2 represent access is error \_R<Q?D+  
} 4]0:zS*O  
SC2LY  
-#/DK   
String sHeader; ]:?S}DRG  
$E^sA|KcT  
Q{uO/6  
for(int i=1;;i++) -]u>kjiIT  
{ GIpYx`mHi  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y&8`NS#_p?  
//Utility.log(in.readLine()); -@#],s7  
sHeader=httpConnection.getHeaderFieldKey(i); <kwF<J  
if(sHeader!=null) v< 2,OcH  
{ V?x&\<;,  
if(sHeader.equals("Content-Length")) E)jd>"  
{ Bd=K40Z:  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (,+#H]L  
break; $t"QLsk0  
} +N+117m  
} *& );-r`.  
else Sw-2vnSdM  
break; Z> Rshtg  
} %Y'/_ esH2  
} q8/k $5E  
catch(IOException e){e.printStackTrace ();} t4:/qy  
catch(Exception e){e.printStackTrace ();} "oZ_1qi<  
=X[?d/[  
KV&6v`K/N  
Utility.log(nFileLength); F 8sOc&L  
Wrp+B[ {r\  
r]D>p&4  
return nFileLength; d`$w3Hy  
} +cmi?~KS*  
}.9a!/@Aj  
\vV]fX   
//保存下载信息(文件指针位置) zI S ,N '  
private void write_nPos() xnWezO_  
{ w^nA/=;r  
try{ `VGw5o  
output = new DataOutputStream(new FileOutputStream(tmpFile)); z%+rI  
output.writeInt(nStartPos.length); [U^Cz{G  
for(int i=0;i<nStartPos.length;i++)  g;AW  
{ b|kL*{;  
// output.writeLong(nPos); `uusUw-Gf  
output.writeLong(fileSplitterFetch.nStartPos); i-4L{T\K  
output.writeLong(fileSplitterFetch.nEndPos); 2MYez>D  
} lAC "7 Z?F  
output.close(); eA?|X|  
} T7/DH  
catch(IOException e){e.printStackTrace ();} eA Fp<2g  
catch(Exception e){e.printStackTrace ();} x]%,?Vd?  
} Gkfzb>_V]  
\k=%G_W  
Oz]$zRu/0  
//读取保存的下载信息(文件指针位置) +CSR!  
private void read_nPos() .Sa=VC?EZ  
{ 0Db=/sJ>  
try{ R!X+-  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gC kR$.-E  
int nCount = input.readInt(); &%/T4$'+Y+  
nStartPos = new long[nCount]; O6b+eS  
nEndPos = new long[nCount]; ?/sn"~"  
for(int i=0;i<nStartPos.length;i++) >z fx2wh\a  
{ })(robBkA  
nStartPos = input.readLong(); !-%%94Q  
nEndPos = input.readLong(); *nHMQ/uf  
} 152s<lu1Z  
input.close(); lm&^`Bn)  
} gy|o#&e]%  
catch(IOException e){e.printStackTrace ();} s)-bOZi  
catch(Exception e){e.printStackTrace ();} 7u :kR;wk  
} 0xCe6{86  
3N2d@R  
DOkuT/+  
private void processErrorCode(int nErrorCode) BAi0w{  
{ w6mYLK%  
System.err.println("Error Code : " + nErrorCode); ZzR0k  
} !>Q\Y`a,*  
^vxNS[C`;  
q?]KZ_a  
//停止文件下载 aAn p7\7  
public void siteStop() 017nhI  
{ \xC#Zs[<  
bStop = true; .Xe_Gp"x  
for(int i=0;i<nStartPos.length;i++) `0q=Z],  
fileSplitterFetch.splitterStop(); 7z/O#Fbs  
4:b'VHW.  
RwrRN+&s\  
} z?|bs?HKS  
} 8+Gwv SDU  
//负责部分文件的抓取 >T0`( #Lm  
**FileSplitterFetch.java #(+V&< K  
*/ s+&0Z3+  
package NetFox; sP% b? 6  
JlRNJ#h>  
WI&}94w  
import java.io.*; .V UnOdI  
import java.net.*; =kK%,Mr  
'`W6U]7>  
zq?xY`E  
public class FileSplitterFetch extends Thread { 8$ X3J[_j  
/?TR_>  
2 1+[9  
String sURL; //File URL Q~' \oWz  
long nStartPos; //File Snippet Start Position UYW'pV  
long nEndPos; //File Snippet End Position e$`hRZ%  
int nThreadID; //Thread's ID WW^+X~Y  
boolean bDownOver = false; //Downing is over r/P}j4)b7  
boolean bStop = false; //Stop identical `@0AGSzUv  
FileAccessI fileAccessI = null; //File Access interface * y wr_9  
7;Q4k"h  
;3bUgI}.J  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3QdCu<eBZ  
{ "i*gJFW|  
this.sURL = sURL; V(io!8,  
this.nStartPos = nStart; R)isWw4  
this.nEndPos = nEnd; 6P,uy;PJ  
nThreadID = id; N:+d=G`x  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `YMd0*  
} SdnO#J}{  
BD^1V( I/  
2vsV :LS.  
public void run() /?z3*x  
{ 9v 8^uPA  
while(nStartPos < nEndPos && !bStop) #<u;.'R  
{ Ra H1aS(  
:l iDoGDi  
&rX#A@=  
try{ C[#C/@  
URL url = new URL(sURL); [9MbNJt 8~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3Z#WAhfS:  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?*7Mn`  
String sProperty = "bytes="+nStartPos+"-"; -g|ji.  
httpConnection.setRequestProperty("RANGE",sProperty); WA:r4V  
Utility.log(sProperty); KU]o=\ak%  
P46Q3EE  
?gjx7TQ?  
InputStream input = httpConnection.getInputStream(); v#X#F9C  
//logResponseHead(httpConnection); .`v%9-5v  
AR$SQ_4  
)%n $_N n  
byte[] b = new byte[1024]; MQ0r ln?  
int nRead; difX7)\  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _F|}=^Z`  
{ g+<[1;[-  
nStartPos += fileAccessI.write(b,0,nRead); r}D#(G$  
//if(nThreadID == 1) Jo~fri([%Q  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0!$y]Gr  
} 3 5L0 CM  
n%4/@M  
(-&d0a9N  
Utility.log("Thread " + nThreadID + " is over!"); hv\Dz*XTs0  
bDownOver = true; Y| ch ;  
//nPos = fileAccessI.write (b,0,nRead); <l5m\A  
} Cz9MXb]B  
catch(Exception e){e.printStackTrace ();} 3hUP>F8  
} V RD^>Gi  
} MHye!T6fO\  
2\gIjXX"  
?N!kYTR%}  
//打印回应的头信息 ~#}T|  
public void logResponseHead(HttpURLConnection con) b`=g#B|  
{ 6qT-  
for(int i=1;;i++) rK:cUW0]X  
{ y=EVpd  
String header=con.getHeaderFieldKey(i); UEfY'%x  
if(header!=null) X|ZAC!J5>  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =_ b/ g  
Utility.log(header+" : "+con.getHeaderField(header)); ;/JXn  
else 0'YP9-C3  
break; g]`YI5  
} wEJzLFCn  
} v=cQ`nou  
3T4HX|rC  
n&?)gKL0g  
public void splitterStop() Dh?I   
{ Z,Us<du  
bStop = true; WjM7s]ZRv  
} (+/d*4  
NuD|%Ebs  
MxKTKBxQ  
} ]yZ%wU9!  
*)6\ V}`  
;^E_BJm  
/* pIYXYQ=Z  
**FileAccess.java .uxM&|0H  
*//文件访问(定位,写) aJA(UN45  
package NetFox; R<{Vgy  
import java.io.*; ;z N1Qb  
+{I" e,Nk  
e t@:-}  
public class FileAccessI implements Serializable{ 0 _MtmmL.  
a'dlA da  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a_?b <  
RandomAccessFile oSavedFile; X?n=UebO^  
long nPos; : T7(sf*!*  
VO=Ibu&X  
uZ\+{j=  
public FileAccessI() throws IOException CS(2bj^6 D  
{ p:W]  
this("",0); .jk A'i@  
} ;e/F( J  
#d-zH:uq  
eNVuw:Q+  
public FileAccessI(String sName,long nPos) throws IOException TB+k[UxB  
{ k,k>w#&  
oSavedFile = new RandomAccessFile(sName,"rw"); P R3Arfle  
this.nPos = nPos; 1# z@D(  
oSavedFile.seek(nPos); @|Yn~PwKs  
} ka8Y+Gs  
voN~f>  
LyWY\K a  
public synchronized int write(byte[] b,int nStart,int nLen) *pv<ZF0>  
{ q^Oj/ws  
int n = -1; dIYf}7P  
try{ 9!W$S[ABRB  
oSavedFile.write(b,nStart,nLen); +jF2 {"  
n = nLen; q#8yU\J|,  
} 2.b,8wT/  
catch(IOException e) W ulyM cJ  
{ bE'{zU}o  
e.printStackTrace (); 0gaHYqkA>}  
} OWT%XUW=  
q` IY;"~  
$[,4Ib_|  
return n; Rb& 9!z  
} gBcs  
] S[?tn  
0F/[GZ<k  
} 3]mprX'  
T]-MrnO  
[xr^t1  
/* 09jE7g @X}  
**SiteInfoBean.java LR>s2zu-  
*/ !U m9ceK  
package NetFox; shH2/.>  
js5VgP`  
P~=yTW  
public class SiteInfoBean { |vl~B|",  
sVw:d _ E  
m:[I$b6AY  
private String sSiteURL; //Site's URL p^<(.+P4  
private String sFilePath; //Saved File's Path jga\Ry=nw  
private String sFileName; //Saved File's Name 9,`i[Dzp  
private int nSplitter; //Count of Splited Downloading File rVoV@,P  
^4^N}7>5  
BO G.[?yx  
public SiteInfoBean() _avf%OS  
{//nSplitter的缺省值为5 |. 0~'  
//default value of nSplitter is 5 _O uNX.yrG  
this("","","",5); M.- {->  
} ?dCwo;~  
4dPTrBQ?  
d9;&Y?fp  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &|#[.ti1  
{ B#jnM~fJz  
sSiteURL= sURL; nv@z;#&  
sFilePath = sPath; k)S1Zs~G  
sFileName = sName; 0 h!Du|?  
this.nSplitter = nSpiltter; # 5)/B  
v>B412l  
__.MS6"N  
} f?)7MR=  
<;PKec  
J*$%d1  
public String getSSiteURL() /[FDiJH2  
{ Zdqm|_R[  
return sSiteURL; |;wc8;  
} gI;"PkN  
)c' 45 bD  
\\KjiT'  
public void setSSiteURL(String value) NF6xKwRU]_  
{ {Fw"y %a^  
sSiteURL = value; Rq5'=L  
} s~A-qG>  
Lxv4w  
U\?D;ABQ%  
public String getSFilePath() ~. vridH  
{ S1U0sP@o  
return sFilePath; (!5Ta7X  
} JpC=ACF  
TsK!36cg  
[-_{3qq<e  
public void setSFilePath(String value) =IsmPQKi  
{ nWIZ0Nde'  
sFilePath = value; rtJER?A  
} K!&W}_@l  
'lA}E  
BKg8p]`+  
public String getSFileName() .s*N1 U?h  
{ F8?2+w@P  
return sFileName; '@.6Rd 8  
} /x ?@M n>  
fe/;U=te  
.b3h?R*&  
public void setSFileName(String value) JVX)>2&$  
{ h{^v756L  
sFileName = value; )4=86>XJT  
} OA&'T*)-A6  
Gc`PO  
H@ 1'El\9  
public int getNSplitter() $kTm"I  
{ x:MwM?  
return nSplitter; s"=TM$Vb  
} I0 ~'z f  
.h=n [`RB  
1Z< ^8L<  
public void setNSplitter(int nCount) 8>e YM  
{ uS`}  
nSplitter = nCount;  O>]i?  
} BJux5Nh  
} r{R<J?Y  
Hq W /  
.t1:;H b  
/* w{*kbGB8s7  
**Utility.java KSchgon0V  
*/ qKfUm:7Q_  
package NetFox; eavn.I8J  
Ra|P5  
l!x+K&  
public class Utility { zX_F+"]THt  
O3o ^%0  
Xs052c|s  
public Utility() metn&  
{ mxgT}L0i  
t8-Nli*O  
)hrsA&1w  
} $WIVCp  
 \nEMj,)  
//线程睡眠 /=p[k^A  
public static void sleep(int nSecond) =Q(J!f  
{ !~vK[G(R  
try{ PG63{  
Thread.sleep(nSecond); i;1pw_K  
} @FN|=?8%  
catch(Exception e) nKm# kb  
{ p [C 9g  
e.printStackTrace (); 0 MK}  
} 5VTVx1P[8  
} aG }oI!  
$vu*# .w  
//日志 -n9&W  
public static void log(String sMsg) ^\ x'4!W  
{ fY&TI}Y  
System.err.println(sMsg); #!F>cez  
} ?A|JKOst]  
wPM>-F  
IQO|)53)  
public static void log(int sMsg) v-z%3x.f  
{ Ih:Q}V#6  
System.err.println(sMsg); dzOco)y  
} 3LETzsJ  
} gvR]"h  
6NX#=A  
H}kZ;8  
/* (s;W>,~q  
**TestMethod.java U~][ ph  
*/ Wm6qy6HR  
package NetFox; ~Q_7HJ=^$  
$.Tn\4z&  
5K1cPU~o_b  
public class TestMethod { O"'xAPQW  
'd$RNqe  
ts,r,{  
public TestMethod() */M`KPW  
{ ///xx/weblogic60b2_win.exe 53:~a  
try{ <8b1OdA  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -SM_JR3<  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $$m0mK  
SiteFileFetch fileFetch = new SiteFileFetch(bean); pZ>yBY?R8>  
fileFetch.start(); [o<hQ`&  
} v>wN O  
catch(Exception e){e.printStackTrace ();} q|<B9Jk  
} 8 z:L<  
$!*>5".A  
} !Sn|!:N4  
?{ExBZNa  
! eZls  
public static void main(String[] args) w U+r]SK@  
{ \~*<[.8~  
new TestMethod(); C}) Dvh  
} Vq+7 /+2"  
} R)66qRf  
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