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http断点续传简单实现(java)

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/* 4 <9=5q]  
**SiteFileFetch.java 1uG"f<TsR  
*/ "&%I)e^  
package NetFox; wi;Br[d  
import java.io.*; ? Fi=P#  
import java.net.*; C^3 <={  
O#b6mKPt;t  
O|\J}rm'  
public class SiteFileFetch extends Thread { c$ao:nP)D  
dUsYZdQs  
$()5VM b  
SiteInfoBean siteInfoBean = null; //文件信息Bean 9Kpa><  
long[] nStartPos; //开始位置 M2d$4-<  
long[] nEndPos; //结束位置 yQU_>_!n  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 FO=4:   
long nFileLength; //文件长度 mN~ci 0  
boolean bFirst = true; //是否第一次取文件 3) 8QS  
boolean bStop = false; //停止标志 34z"Pm  
File tmpFile; //文件下载的临时信息 b$4"i XSQ  
DataOutputStream output; //输出到文件的输出流 XnDUa3  
K:!"+q  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) V\{clJ\U  
public SiteFileFetch(SiteInfoBean bean) throws IOException ~s% Md  
{ 'U1R\86M  
siteInfoBean = bean; ADS9DiX/  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); OSlvwH%(EE  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); M}d_I+  
if(tmpFile.exists ()) %Qc La//  
{ Hcl(3> Jn2  
bFirst = false; K$>%e36Cc  
read_nPos(); ->sm+H-*  
} (gy#js #  
else cFaaLUZk  
{ l9}3XI.=  
nStartPos = new long[bean.getNSplitter()]; kv3E4,<9  
nEndPos = new long[bean.getNSplitter()]; I2TaT(e\  
} K17j$o^6KK  
TX$r `~  
Gnf~u[T6  
~kShq%  
} 6,)[+Bl  
[ad@*KFxy3  
Z8zmHc"IH  
public void run() aIJt0;  
{ T@G?t0  
//获得文件长度 -j%,Oo  
//分割文件 TFH\K{DM  
//实例FileSplitterFetch :axRoRg  
//启动FileSplitterFetch线程 a&tSj35*6  
//等待子线程返回  U mNa[ s  
try{ 9  TvV=  
if(bFirst) "^4_@ oo  
{ }v Z+A  
nFileLength = getFileSize(); |?rNy=P,  
if(nFileLength == -1) Du`JaJI  
{ %C$% !C  
System.err.println("File Length is not known!"); |kw)KEi}H  
} sp#p8@Cj  
else if(nFileLength == -2) }lh I\q  
{ 0*rQ3Z  
System.err.println("File is not access!"); |o{:ZmzM  
} |K6REkzr  
else )>.&N[v  
{ <Fi%iA  
for(int i=0;i<nStartPos.length;i++) gXYI\.  
{ 3{""58  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); \Kl+ 5%L  
} i 7_ _  
for(int i=0;i<nEndPos.length-1;i++) /e7O$L)   
{ ^.#jF#u~  
nEndPos = nStartPos[i+1]; J/\V%~ 1F  
} fIj|4a+  
nEndPos[nEndPos.length-1] = nFileLength; nN*w~f"  
} QrfG^GID  
} 'qjeXqGH$  
JQV%fTHS  
LA@w:Fg  
//启动子线程 yHs- h   
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dQ_!)f&w1  
for(int i=0;i<nStartPos.length;i++) O$IEn/%+  
{ F{EnOr`,m=  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \]=7!RQ\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kB/D!1 "  
nStartPos,nEndPos,i); ,=tD8@a<  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |p><'Q% *  
fileSplitterFetch.start(); KHgBo}6  
} @n(Z$)8tR  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l7W 6qNB  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pdt6nzfr  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZkAU17f  
nEndPos = " + nFileLength); D[^m{ 9_  
// fileSplitterFetch[nPos.length-1].start(); 5!l0zLQP o  
w S4.8iJ  
RT)d]u  
//等待子线程结束 Fe]B&n  
//int count = 0; Rn{iaM2Y<  
//是否结束while循环 T'4z=Z]w  
boolean breakWhile = false; +w.JpbQ&  
I 4,K43|  
FP;Ccl"s  
while(!bStop) AI,(z;{P  
{ U7oo$gW%|T  
write_nPos(); Hz.(qW">5*  
Utility.sleep(500); QS{1CC9$  
breakWhile = true; u[ L`-zI  
3 |hHR  
7 qj9&bEy  
for(int i=0;i<nStartPos.length;i++) oXxCXO,q  
{ J]&y$?C  
if(!fileSplitterFetch.bDownOver) 'h^0HE\~p  
{ ^1Zeb$Nw'  
breakWhile = false; #$c Rkw  
break; |g #K]v  
} bzX\IrJpOZ  
} 6ek;8dL  
if(breakWhile) JMH8MH*  
break; 5dB'&8DX  
D9FJ 1~  
c0hwc1kv-  
//count++; @6mBqcE'?  
//if(count>4) d/ bEt&  
// siteStop(); yqi^>Ce0  
} W Dg+J  
hir4ZO%Zt  
pek%08VSEU  
System.err.println("文件下载结束!"); #B:hPZM1  
} #|*F1K  
catch(Exception e){e.printStackTrace ();} %,Ap7X3:QT  
} :{oZ~<  
~-PjW#J%  
JaK}|  
//获得文件长度 ,t`Kv1  
public long getFileSize() TZ2=O<Kj  
{ :'*DPB-  
int nFileLength = -1; 7vABq(  
try{ `67[O4$<  
URL url = new URL(siteInfoBean.getSSiteURL()); 6IWxPt ~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {%IExPJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); r=6v`)Qr  
/)dFK~  
|\U5) ,m  
int responseCode=httpConnection.getResponseCode(); )l!3(  
if(responseCode>=400) DqX{'jj  
{ u$-U*r  
processErrorCode(responseCode); zOGU8Wg  
return -2; //-2 represent access is error (iR ide  
} I =1+h  
Clh!gpB c  
<<i3r|}  
String sHeader; (y M^  
BM(]QUxRd  
'3<fsK=  
for(int i=1;;i++) w^LuIbA  
{ 7DIIx}A  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jLpc Zb,  
//Utility.log(in.readLine()); cCa|YW^j  
sHeader=httpConnection.getHeaderFieldKey(i); NcP.;u;`  
if(sHeader!=null) gS:A'@&  
{ Oi:<~E[kz.  
if(sHeader.equals("Content-Length")) ^D<r  
{ Ur5FC r  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "m^' &L  
break; ^`G`phd$  
} TEMw8@b  
} 1P(|[W1  
else TOoQZTI  
break; r\blyWi  
} i:Zm*+Gi  
} $2u 'N:o  
catch(IOException e){e.printStackTrace ();} +e-G,%>9  
catch(Exception e){e.printStackTrace ();} jiYmb8Q4D  
ZKXo-~=>  
fgBM_c&9T  
Utility.log(nFileLength); c7M%xGrP  
!w H'b  
C#H:-Q&  
return nFileLength; i| ZceX/  
} mWyqG*-Hb  
%~jkB.\* )  
<D::9c j  
//保存下载信息(文件指针位置) KX}Rr7a  
private void write_nPos() RKPD4e>%  
{ h68]=KyK  
try{ .58qL-iC  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4WE6fJ2X  
output.writeInt(nStartPos.length); gt/zpiKmV  
for(int i=0;i<nStartPos.length;i++) ;L,mBQB?0b  
{ Y& F=t/U2  
// output.writeLong(nPos); &`fhEN  
output.writeLong(fileSplitterFetch.nStartPos); 4[BG#  
output.writeLong(fileSplitterFetch.nEndPos); QjC22lW-  
} gl]E_%tH  
output.close(); cetvQAGXY  
} {O+Kw<d  
catch(IOException e){e.printStackTrace ();} JMVNmq&0  
catch(Exception e){e.printStackTrace ();} NHl|x4Zpw  
} 8@PX7!9  
+n7?S~R$  
l27\diKPJ  
//读取保存的下载信息(文件指针位置) TuW/N L|  
private void read_nPos() .S%0   
{ JkGnKm9G  
try{ %%Qo2^-  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); rY p3(k3  
int nCount = input.readInt(); Fh*j#*oe  
nStartPos = new long[nCount]; wQ%mN[  
nEndPos = new long[nCount]; [|lB5gi4t!  
for(int i=0;i<nStartPos.length;i++) doB  
{ 7^M9qTEHp  
nStartPos = input.readLong(); /l{ &iLz[  
nEndPos = input.readLong(); m~>Y{F2  
} 7#~+@'Oe  
input.close(); t#S<iBAZ  
} ay %KE=*v  
catch(IOException e){e.printStackTrace ();} <&!v1yR  
catch(Exception e){e.printStackTrace ();} 7Su#Je]  
} YhRWz=l  
Dk='+\  
sO5?aB&  
private void processErrorCode(int nErrorCode) o=RM-tR`v  
{ zz^F k&  
System.err.println("Error Code : " + nErrorCode); 5P .qXA"D  
} JMCW}bA  
qiZO _=0  
gh>>Ibf  
//停止文件下载 IQ!\w-  
public void siteStop() gaf$uT2  
{ /1 RAAa  
bStop = true; x)UwV  
for(int i=0;i<nStartPos.length;i++) !J =sk4T  
fileSplitterFetch.splitterStop(); 4HAp{a1  
||zb6|7I4  
h!#:$|Q  
} Sggq3l$Qc  
} 0oh]61g C  
//负责部分文件的抓取 E0/mSm"(T  
**FileSplitterFetch.java Z--@.IYoJ  
*/ 9z I.pv+]  
package NetFox; `y+-H|%?  
1.D-FPK  
CdUAy|!`R  
import java.io.*; N-g8}03  
import java.net.*; {} Bf   
j&UMjI9[  
"/]| Hhc{  
public class FileSplitterFetch extends Thread { v?c 0[+?  
g}f9dB,F  
Bk}><H  
String sURL; //File URL dtPoo\@  
long nStartPos; //File Snippet Start Position IG?'zppjd6  
long nEndPos; //File Snippet End Position JxjI]SF02  
int nThreadID; //Thread's ID " v}pdUW  
boolean bDownOver = false; //Downing is over xvNo(>  
boolean bStop = false; //Stop identical f/kI| Z  
FileAccessI fileAccessI = null; //File Access interface W- $a Y2  
5/QRL\  
NWfAxkz {/  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XM<KF &pVB  
{ x"4} isp<  
this.sURL = sURL; \7z^!m  
this.nStartPos = nStart; <} jPXEB"  
this.nEndPos = nEnd; =H8 xSJLh  
nThreadID = id; 4gSH(*}  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ICB~_O5  
} jEz+1Nl)  
@=5qT]%U3J  
nJ?^?M'F%  
public void run() L&-hXGx=7  
{ 0e[d=)XG  
while(nStartPos < nEndPos && !bStop) =o p%8NJf  
{ qi^!GA'5j  
^Cv^yTj;&  
d/74{.  
try{ O8U<{jgAG  
URL url = new URL(sURL); ,uz ]V1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B$?qQ|0:=  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?4G|+yby  
String sProperty = "bytes="+nStartPos+"-"; Zs2-u^3&  
httpConnection.setRequestProperty("RANGE",sProperty); I =Wc&1g  
Utility.log(sProperty); OOBhbpg!D  
Zc"B0_&?:7  
Q/I)V2a1i  
InputStream input = httpConnection.getInputStream(); >\<*4J$PZ  
//logResponseHead(httpConnection); }]UB;id'  
: t$l.+B  
qP!P +'B  
byte[] b = new byte[1024]; S<nq8Ebmw  
int nRead; _)$PKOzbb  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) A\Txb_x  
{ @^ ik[9^H  
nStartPos += fileAccessI.write(b,0,nRead); 2}vg U$a  
//if(nThreadID == 1) #(LfYw.P1V  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O;[9_[  
} "tS'b+SJ-S  
ZiFooA  
'j%F]CK  
Utility.log("Thread " + nThreadID + " is over!"); #kkY@k$4  
bDownOver = true; ExHAY|UA  
//nPos = fileAccessI.write (b,0,nRead); XH7xT@  
} ?R Fg$Z'^  
catch(Exception e){e.printStackTrace ();} K:y^OAZfV  
} :RxHw;!  
} s,*c@1f?  
DZ ^1s~  
s]27l3)B  
//打印回应的头信息 fR-C0"c  
public void logResponseHead(HttpURLConnection con) W</n=D<,I  
{ }i!pL(8;  
for(int i=1;;i++) )<4_:  
{ {}>n{_  
String header=con.getHeaderFieldKey(i); ^] p  
if(header!=null) /DS?}I.*]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Wx)K* 9  
Utility.log(header+" : "+con.getHeaderField(header)); 4YU/uQm  
else sTHq&(hLUG  
break; o=fgin/E\  
} smAC,-6 ]~  
} ^a9 oKI9n  
_'x8M  
R@T6U:1  
public void splitterStop() +:jT=V"X  
{ [IM%b~j(^  
bStop = true; O,V9R rG  
} #6S75{rnW"  
MN= sIP,zk  
JbQZ!+  
} ^%oUmwP<$  
b1^n KB  
VFD%h }  
/* MN;/*t  
**FileAccess.java cJ}QXuuUv  
*//文件访问(定位,写) oholt/gb+0  
package NetFox; CidM(  
import java.io.*; eo#^L}  
;@4H5p  
GtI6[ :1t  
public class FileAccessI implements Serializable{ 6DSH`-;  
{6vEEU  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |@VF.)_  
RandomAccessFile oSavedFile; bNzqls$  
long nPos; }3/~x  
J>S3sP  
%.x@gi q  
public FileAccessI() throws IOException h!]"R<QQdu  
{ X.|Ygx  
this("",0); v1[_}N9f>H  
} 0^!Gib  
hY \{|  
nZvU 'k:  
public FileAccessI(String sName,long nPos) throws IOException J0<p4%Cf  
{ f5dR 5G  
oSavedFile = new RandomAccessFile(sName,"rw"); l`n5~Fs  
this.nPos = nPos; a, Kky ^B  
oSavedFile.seek(nPos); j=sBq.S  
} )GB`*M[   
/-*hjX$n  
\MYU<6{u  
public synchronized int write(byte[] b,int nStart,int nLen) KHj6Tg;)  
{ 6!7Pm>ml  
int n = -1; +$beo2x6  
try{ I ,FqN}  
oSavedFile.write(b,nStart,nLen); M?6;|-HH  
n = nLen; x(r+P9f\<  
} 99ASIC!  
catch(IOException e) KjR4=9MD  
{ Uxl(96  
e.printStackTrace (); L=1 ~ f-  
} $-pbw@7  
b 6W#SpCF  
4Z%Y"PL(K  
return n; X.J  
} 2)LX^?7R  
/(6zsq'v|  
}ymvC  
} #Q6w+"  
]if;A)'  
{/UhUG  
/* I"Q<n[g0'  
**SiteInfoBean.java ua& @GXvZ  
*/ U}P,EP%p  
package NetFox; Kmry=`=A  
LcUlc)YH5  
r\mPIr|  
public class SiteInfoBean { j 2}v}  
(wL3 +  
X5E '*W  
private String sSiteURL; //Site's URL i-13~Dk  
private String sFilePath; //Saved File's Path !UNNjBBP7  
private String sFileName; //Saved File's Name ^8742.  
private int nSplitter; //Count of Splited Downloading File ?V+wjw  
(Pz8 iz  
R7aXR\ R  
public SiteInfoBean() STT2o=   
{//nSplitter的缺省值为5 XJFnih  
//default value of nSplitter is 5 1i,4".h?M  
this("","","",5); wu^q`!ml  
} 6F5,3&  
Dc:DY:L^  
r@$B'CsLj  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,C!n}+27  
{ *)%dXVf  
sSiteURL= sURL; i_Ar<9a~  
sFilePath = sPath; wznn #j  
sFileName = sName; t,Q'S`eTU  
this.nSplitter = nSpiltter; ,8`O7V{W  
Q&wYc{TUbm  
+u#Sl)F  
} cdp{W  
qhxC 5f4Z  
$h]NXC6J  
public String getSSiteURL() j];G*-iv{  
{ Ut;'Gk  
return sSiteURL; 0Q3YN(  
} Qdm(q:w  
T{;=#rG<  
u9@b <  
public void setSSiteURL(String value) \)GR\~z0h  
{ d"l}Ny)C  
sSiteURL = value; 9TW8o}k`  
} $P_x v  
K Dz]wNf  
O 'Am RJ  
public String getSFilePath() M/)B" q  
{ .r*#OUC  
return sFilePath; .]zw*t*  
} 0w+5'lOg  
 L,%Z9  
5])8qb/F  
public void setSFilePath(String value) ytob/tc  
{ r?]%d!   
sFilePath = value; K /8qB~J*  
} |87W*  
d{l{P] nr  
8LeK wb  
public String getSFileName() TL]bY'%  
{ m/KjJ"s,  
return sFileName; ,=x RoXYB}  
} ?}v}U^  
lnjL7x  
`L;OY 4  
public void setSFileName(String value) Bjtj{B  
{ 0ovZ&l  
sFileName = value; 67fIIXk&  
} 2$  
-2z,cj&E{  
Qv\bLR  
public int getNSplitter() :`;(p{  
{ !2wETs?  
return nSplitter; VZIKjrKs  
} uGM>C"  
?&XzW+(X  
E"ZEo9y@^  
public void setNSplitter(int nCount) `fLfT'  
{ S>(z\`1qm  
nSplitter = nCount; -#daBx ?  
} m_(E(_  
} wJ/ ~q)  
G IK u  
QT7_x`#J~o  
/* s5nB(L*Pjp  
**Utility.java 8KZ$ F>T]>  
*/ Pb3EnNqYbM  
package NetFox; Z%KL[R}^w;  
|E? ,xWN  
|c=d;+  
public class Utility { )4Bwt`VX  
S'|lU@P Cl  
:82?'aR  
public Utility() \3L$I-]m  
{ N:twq&[Y  
oO8]lHS?@  
Z0{f  
} oy`3r5g   
EgFl="0  
//线程睡眠 l<s :%%CX  
public static void sleep(int nSecond) " S ?Km  
{ >J9IRAm}sc  
try{ JXlTN[O  
Thread.sleep(nSecond); gZ1N&/9;  
} %bEGv:88s  
catch(Exception e) i_|h{JK)  
{ *m iONc  
e.printStackTrace (); =z+-l5Gu"  
}  {`tHJ|8  
} vY4WQbz(  
0 PR4g}"  
//日志 |&9tU  
public static void log(String sMsg) l.sm~/  
{ ]~$c~*0g  
System.err.println(sMsg); gv`%Z8u(  
} ]aREQ?ma&z  
*X%?3"WH8  
sV]i/B  
public static void log(int sMsg) @wg&6uQ  
{ Ml'bZLwq  
System.err.println(sMsg); loml.e=87  
} rve7YS'  
} jM{qRfOrg  
"vv$%^  
'\Qf,%%.  
/* @ysJt  
**TestMethod.java ;|Y2r^c  
*/ D WsCYo  
package NetFox; GH [ U!J  
U&w*Sb"  
6wa<'!   
public class TestMethod { 8''9@xz  
<{3q{VW*  
7Ntjx(b$"h  
public TestMethod()  s$K@X `  
{ ///xx/weblogic60b2_win.exe FEge+`{,  
try{ 'SsPx&)l  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P9 W<gIO  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Dh*~U :6$g  
SiteFileFetch fileFetch = new SiteFileFetch(bean); n P0Ziu'{  
fileFetch.start(); C~3@M<X  
} a.5zdoH_  
catch(Exception e){e.printStackTrace ();} b>G qNf!  
>^M!@=/?J  
I|Vk.,  
} N )b|  
at_dmU2[7  
5JJg"yuY"  
public static void main(String[] args) J R 8 Z6  
{ s@*,r@<  
new TestMethod(); X; e`y:9  
} -`<6=[QUO  
} 8Cf^$  
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