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http断点续传简单实现(java)

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/* ?Thh7#7LM  
**SiteFileFetch.java eiJ 13`T  
*/ )S;pYVVAl  
package NetFox; l".LtUf-  
import java.io.*; Ob"48{w$  
import java.net.*; l*`2 EJ  
MY[QYBkn}  
?IWLH-fkP  
public class SiteFileFetch extends Thread { Sl?@c/Ng  
m1mA:R\zM  
k_^| %xJ  
SiteInfoBean siteInfoBean = null; //文件信息Bean 7vRFF@eq}  
long[] nStartPos; //开始位置 $Z!$E,@c  
long[] nEndPos; //结束位置 ve [*t`  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 g=T !fF=  
long nFileLength; //文件长度 <]jKpJ{3N  
boolean bFirst = true; //是否第一次取文件 #@*;Y(9Ol  
boolean bStop = false; //停止标志  9z9EK'g  
File tmpFile; //文件下载的临时信息 w[bhm$SX]B  
DataOutputStream output; //输出到文件的输出流 c%N8|!e  
P}AfXgr  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) -f+U:/'.>v  
public SiteFileFetch(SiteInfoBean bean) throws IOException xM dbS4&!  
{ (H\)BS7#R  
siteInfoBean = bean; e B$ S d  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); l20fA-T _I  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 0\N n.x%  
if(tmpFile.exists ()) TbY <(wrMZ  
{ ac-R q.GQY  
bFirst = false; VhWF(*  
read_nPos(); 5V|D%t2N  
} lBbUA)z6  
else Z;nbnRz  
{ ]Ywj@-*q  
nStartPos = new long[bean.getNSplitter()]; SP,#KyWP0)  
nEndPos = new long[bean.getNSplitter()]; P2q'P&  
} `pHlGbrW  
LZ97nvK  
b*7:{ FXg  
.fQ/a`AsU  
} I(cy<ey+e  
o]#M8)=  
XpFo SW#K  
public void run() OJkiTs{  
{ jP]I>Tq  
//获得文件长度 3kl<~O|Fs  
//分割文件 ^X&n-ui   
//实例FileSplitterFetch rM sd)  
//启动FileSplitterFetch线程 WxN@&g(  
//等待子线程返回 rW~hFSrV[o  
try{ eC9nOwp]xH  
if(bFirst) Jj~c&LxrO  
{ ?\ qfuA9.  
nFileLength = getFileSize(); 'q#$^ ='o  
if(nFileLength == -1) j"8f,er  
{ @dy<=bh~  
System.err.println("File Length is not known!"); `YZK$ -,  
} tKnvNOhn  
else if(nFileLength == -2) m_ |:tU(t  
{ (#dwIBBFt  
System.err.println("File is not access!"); F|eKt/>e  
} kiW|h)w_,v  
else ]/o0p  
{ tP?pN]Q$,  
for(int i=0;i<nStartPos.length;i++) t3~ZGOn  
{ <`B4+:;w6  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |Ew~3-u!  
} ^* xhbM;  
for(int i=0;i<nEndPos.length-1;i++) d:U2b"k=/u  
{ YPjjSi:#  
nEndPos = nStartPos[i+1]; K%XQdMv  
} $yZ(c#L  
nEndPos[nEndPos.length-1] = nFileLength; 9^;)~ G  
} \Bg;^6U  
} ^x! N]  
iK#5nY].  
Q\P?[i]  
//启动子线程 ^`W8>czi  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5$v,%~$Xds  
for(int i=0;i<nStartPos.length;i++) '^T Q Ubw  
{ y?ps+ce93  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OZ/P@`kN.f  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {Z529Ns  
nStartPos,nEndPos,i); D[m+= -  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P,$|.p d'  
fileSplitterFetch.start(); A]z~Dw3  
} {Hv/|.),hu  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Px!M^ T!Pi  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D!K){ E  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ST#OO!  
nEndPos = " + nFileLength); (XQBBt  
// fileSplitterFetch[nPos.length-1].start(); q'07  
)zFPf]gz  
&8l"Dl  
//等待子线程结束 j^t#>tZS  
//int count = 0; F__(iXxC  
//是否结束while循环 z,6X{=  
boolean breakWhile = false; x=UwyZ  
u afSz@`  
ICJp-  
while(!bStop) xKilTh_.6  
{ ?!N@%R>5rN  
write_nPos(); M^i^_}~S;  
Utility.sleep(500); ;1S~'B&1Q  
breakWhile = true; 52*9q!  
EJdl%j  
`^rN"\  
for(int i=0;i<nStartPos.length;i++) =~)J:x\F  
{ X+'z@xpj  
if(!fileSplitterFetch.bDownOver) NTnjVU }  
{ =@98Gl9!  
breakWhile = false; Js`xTH'  
break; .L,xqd[zC  
} 0 i76(2  
} 7J 0=HbH  
if(breakWhile) QKj-"y[  
break; `zr%+  
bNUb  
mkA1Sh{hX>  
//count++; //SH=>w2  
//if(count>4) x@-bY  
// siteStop(); T-0[P;  
} + _=&7  
$ekB+ t:cj  
?2Q9z-$  
System.err.println("文件下载结束!"); tBtG- X2  
} ;.=ZwM]C  
catch(Exception e){e.printStackTrace ();} 3GH@|id  
} 3?Ml]=u  
=hs !t|(*  
n=HId:XT  
//获得文件长度 `Qf$]Eoft  
public long getFileSize() Kq`C5  
{ y^7ol;t  
int nFileLength = -1; C'HW`rh.^  
try{ C%s+o0b  
URL url = new URL(siteInfoBean.getSSiteURL()); qIbp0`m  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0P(U^rkR~  
httpConnection.setRequestProperty("User-Agent","NetFox"); /H_,1Fu|  
E0;KTcZi  
kC =e>v  
int responseCode=httpConnection.getResponseCode(); ~! *xi  
if(responseCode>=400) < a g|#  
{ M;BDo(1  
processErrorCode(responseCode); NVEjUt/  
return -2; //-2 represent access is error +- ~:E_G  
} =B}a +0u!  
#WBlEVx;Z  
2OXcP!\Y  
String sHeader; @a AR99M  
#Y*?k TF  
41c]o<!=)j  
for(int i=1;;i++) -ZTe#@J  
{ I~LN)hqdo  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w\ hl2JTy  
//Utility.log(in.readLine()); pYtG%<  
sHeader=httpConnection.getHeaderFieldKey(i); }b9"&io  
if(sHeader!=null) c7$L:  
{ )7U^&I,  
if(sHeader.equals("Content-Length")) [@!.(Hp  
{ 8 |>$M  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :r?gD2q  
break; &RRHmJI:  
} g7($lt>  
} sV8}Gv a  
else XcOfQ s  
break; =0te.io)3O  
} 7Ao9MF-  
} gWt}q-@nRR  
catch(IOException e){e.printStackTrace ();} J%G EIe|  
catch(Exception e){e.printStackTrace ();} vwVK ^B  
 ~F?vf@k  
/az}<r8  
Utility.log(nFileLength); ]*I:N  
Z`5jX;Z!  
#;9I3,@/Y  
return nFileLength; ?2hS<qXX  
} m `"^d #  
 %2 A-u  
M2K{{pGJ[&  
//保存下载信息(文件指针位置) :%[=v (G[  
private void write_nPos() q=NI}k  
{ 9"KO!w  
try{ hf6=`M}>i  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~r<@`[-L  
output.writeInt(nStartPos.length); x -wIgo+  
for(int i=0;i<nStartPos.length;i++) g@IV|C( *0  
{  1 &24:&  
// output.writeLong(nPos); YCv)DW;  
output.writeLong(fileSplitterFetch.nStartPos); Tr}z&efY  
output.writeLong(fileSplitterFetch.nEndPos); 6OBe^/ZRt  
} d~i WV6Va  
output.close(); Vu @2  
} &`#k 1t'  
catch(IOException e){e.printStackTrace ();} H .F-mm  
catch(Exception e){e.printStackTrace ();} zV)(i<Q  
} W'aZw9  
UKYQ @m  
}6;K+INT  
//读取保存的下载信息(文件指针位置) q|An  
private void read_nPos() 8nt3S m  
{ {M`yYeo  
try{ 7Hghn"ol  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "gm[q."n<  
int nCount = input.readInt(); C,*3a`/2M^  
nStartPos = new long[nCount]; HGuU6@~hu  
nEndPos = new long[nCount]; ~d0:>8zQR  
for(int i=0;i<nStartPos.length;i++) OT1  
{ ~UrKyA  
nStartPos = input.readLong(); 9YpgzCx Z  
nEndPos = input.readLong(); bW"bkA80  
} Wo&WO e  
input.close(); 2nNBX2 o&_  
}  8*nv+  
catch(IOException e){e.printStackTrace ();} jZjWz1+  
catch(Exception e){e.printStackTrace ();} o!R.QI^2VT  
} r]e1a\)r  
Ban@$uf  
yyp0GV.x  
private void processErrorCode(int nErrorCode) xJG&vOf;?  
{ -^1}J  
System.err.println("Error Code : " + nErrorCode); 9CBKU4JQ  
} r7Vt,{4/  
w}8 ,ICL  
tcDWx:Q  
//停止文件下载 9v\x&h  
public void siteStop() vY 0EffZ  
{ i D6f/|g  
bStop = true; -L4fp  
for(int i=0;i<nStartPos.length;i++) (`W_ -PI  
fileSplitterFetch.splitterStop(); 7a$K@iWU  
j6!C/UgQ  
xwuGJ   
} [ B{F(~O  
} #7 )&`  
//负责部分文件的抓取 6MCLm.L  
**FileSplitterFetch.java ///  
*/ \,UpFuU\  
package NetFox; {Ad4H[]|]  
AnF"+<  
Sb2hM~  
import java.io.*; ;jgk53lo  
import java.net.*; UL{+mp  
0+-"9pED>E  
1c5+X Cr  
public class FileSplitterFetch extends Thread { ae%Bl[  
OC?a[^hB^)  
?;GbK2\bj  
String sURL; //File URL YC!IIE_  
long nStartPos; //File Snippet Start Position .<m${yU{3  
long nEndPos; //File Snippet End Position _GhP{ C$  
int nThreadID; //Thread's ID |IcA8[  
boolean bDownOver = false; //Downing is over 0oNNEC  
boolean bStop = false; //Stop identical L3/SIoqd  
FileAccessI fileAccessI = null; //File Access interface ^}w@&Bje  
v3p0  
*F<Ar\f5  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (Q]Ww_r~  
{ |wxAdPe  
this.sURL = sURL; Abw=x4d(i  
this.nStartPos = nStart; V 4#bW  
this.nEndPos = nEnd; G '1K6  
nThreadID = id; 3_DwqZ 'O  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -dto46X  
} ;J uBybJb  
MG}rvzn@  
V=i/cI\  
public void run() D`Cy]j  
{ GhJ<L3  
while(nStartPos < nEndPos && !bStop) Y>J$OA:  
{ q1a*6*YB  
{4F=].!  
QZh#&Qf;  
try{ e2"<3  
URL url = new URL(sURL); z|M+ FHl$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vVbBg; {  
httpConnection.setRequestProperty("User-Agent","NetFox"); .](~dVp%~  
String sProperty = "bytes="+nStartPos+"-"; @u>:(9bp  
httpConnection.setRequestProperty("RANGE",sProperty); gzMp&J  
Utility.log(sProperty); |e QwI&  
KgH_-REN  
1 $m[# 3  
InputStream input = httpConnection.getInputStream(); +L\Dh.Ir  
//logResponseHead(httpConnection); 3(oB[9]s  
@<TC+M5!  
QmKEl|/{u  
byte[] b = new byte[1024]; nk*T x  
int nRead; kEYkd@ {  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _:1s7EC  
{ tLE7s_^  
nStartPos += fileAccessI.write(b,0,nRead); g`Kh&|GU  
//if(nThreadID == 1) 1 u~Xk?  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [mcER4]}  
} ;RW0Dn)Q  
I^GZ9@UE  
qNuBK6E#4  
Utility.log("Thread " + nThreadID + " is over!"); I.6 qA *  
bDownOver = true; , 3&D A  
//nPos = fileAccessI.write (b,0,nRead); #?h-<KQQ  
} S'_2o?fs  
catch(Exception e){e.printStackTrace ();} TpGnSD  
} 6/dP)"a('  
} V[;^{,;  
u|+Dqe`  
|e_'% d&  
//打印回应的头信息 `C&@6{L  
public void logResponseHead(HttpURLConnection con) PL|ea~/  
{ {9XN\v=$"*  
for(int i=1;;i++) ?APCDZ^  
{ &SW~4{n:  
String header=con.getHeaderFieldKey(i); 4T>d%Tt+)  
if(header!=null) hnnVp_<]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oFi_ op  
Utility.log(header+" : "+con.getHeaderField(header)); D~zk2  
else g QYs,  
break; e9;5.m  
} X/f?=U  
} [gIvB<Uv  
XY,!vLjL  
s$Vz1B  
public void splitterStop() ^2`*1el  
{ {nj`>  
bStop = true; ,UNnz&H+f  
} IMSLHwZ  
#G]g  
O %1uBc  
} or`D-x)+@  
LlcH#L$  
$ vBFs]h  
/* tx$`1KA  
**FileAccess.java b?j\YX[e  
*//文件访问(定位,写) P]0/S  
package NetFox; aeE~[m  
import java.io.*; i<M F8 $  
YJF|J2u  
MmQk@~  
public class FileAccessI implements Serializable{ xz-?sD/xe  
Sg< B+u\\  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^4C djMF-E  
RandomAccessFile oSavedFile; zwJ\F '  
long nPos; /[I#3|  
J%IKdxa  
owzcc-g  
public FileAccessI() throws IOException R9-Uoc/  
{ 5i-VnG  
this("",0); .wPI%5D  
} &<EixDi4q  
1oI2  
{ceY:49  
public FileAccessI(String sName,long nPos) throws IOException BUUc9&f3o  
{ Ae* 6&R4  
oSavedFile = new RandomAccessFile(sName,"rw"); G4^6o[x  
this.nPos = nPos; g*;z V i  
oSavedFile.seek(nPos); g~XR#vl$  
} ^|(VI0KO  
pHKc9VC  
YJ}9VY<}1K  
public synchronized int write(byte[] b,int nStart,int nLen) C$d b) 5-  
{ _ZE&W  
int n = -1; ZU;nXqjc  
try{ _2WW0  
oSavedFile.write(b,nStart,nLen); ujr"_ofI  
n = nLen; lv#L+}T  
} y\=^pla  
catch(IOException e) eyy%2> b  
{ < =!FB8 .  
e.printStackTrace (); Q[9W{l+  
} 24k;.o  
A&{eC C  
\F14]`i  
return n; 9?uU%9r5P  
} jd.w7.8  
r` sG!  
s=Xg6D  
} -0+h&CO  
B D [<>Wm  
C3KAQ U  
/* ]f6,4[  
**SiteInfoBean.java [*g'Y;W  
*/ H-3*},9  
package NetFox; usw(]CnH  
!O4)Y M  
TiKfIv  
public class SiteInfoBean { w& )ApfL  
4veXg/l  
L0*f(H  
private String sSiteURL; //Site's URL ++BQ==@  
private String sFilePath; //Saved File's Path 2p~G][  
private String sFileName; //Saved File's Name ^*F'[!. p  
private int nSplitter; //Count of Splited Downloading File zqLOwzMlLx  
{[bB$~7Eu  
v7<r- <I[  
public SiteInfoBean() p3qKtMs0!  
{//nSplitter的缺省值为5 g6@^n$Y  
//default value of nSplitter is 5 'jYKfq~_cJ  
this("","","",5); e\ }'i-  
} @=K*gbq5  
{d%hkbN+{  
!.7m4mKzo  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #'I<q  
{ lt%9Zgr[u  
sSiteURL= sURL; Ue=1NnRDkA  
sFilePath = sPath; cHJ4[x=  
sFileName = sName; Y8/&1s_  
this.nSplitter = nSpiltter; u6 4{w,  
p+CK+m   
!gi3J @  
} d!y_N&z|(  
{(Ba  
e!w#{</8Q  
public String getSSiteURL() i<!1s%i}  
{ T/tCX[}  
return sSiteURL; R#Z m[S  
} 6%&DJBU!  
a[J_H$6H!  
?>mpUH  
public void setSSiteURL(String value) cK75Chsu  
{ V=E5pB`Pr  
sSiteURL = value; j3fq}>=  
} B %  
AIw~@*T  
|5*:ThC[  
public String getSFilePath() <W/YC 2b  
{ :MGIp%3  
return sFilePath; =/ 19 -Y:  
} }ok'd=M  
[jTZxH<  
)Mh5q&ow  
public void setSFilePath(String value) {"_V,HmEF+  
{ ]:Pkh./  
sFilePath = value; 1n#{c5T  
} )H{OqZZYD  
;pG5zRe  
<<&SyP  
public String getSFileName() cUwR6I9  
{ {<Xl57w-Q  
return sFileName; ZFtN~Tg  
} h_B  nQZ\  
Efu/v<  
|9mGX9q  
public void setSFileName(String value) C^!~WFy  
{ k>#-NPU$  
sFileName = value; u+ 8wBb5!  
} 5yf`3vV|3@  
b7HT<$Wg  
UZo[]$"Q`  
public int getNSplitter() 8< z   
{ \j0016;  
return nSplitter; nr%P11U\c  
} c22L]Sxo  
dl+c+w"  
O`.IE? h#  
public void setNSplitter(int nCount) l?KP /0`  
{ $Q`\-  
nSplitter = nCount; VW:Voc  
} >| hqt8lY  
} Agwl2AM5k  
Pk^V6-  
C+0BV~7J<<  
/* c  
**Utility.java >t4<2|!(M  
*/ *-@@t+3  
package NetFox; Pk:b:(4  
9)'wgI#  
H4BuxM_r  
public class Utility { +[#^c3x2  
fAD {sg  
(n2=.9k!  
public Utility() [L?WM>]%  
{ VQbKrnX  
@Dd3mWKq  
1+Bj` ACP  
} YGZa##i  
*-s':('R  
//线程睡眠 &izk$~  
public static void sleep(int nSecond) 8zpTCae^=7  
{ `'ak/%Krh  
try{ $ 3R5p  
Thread.sleep(nSecond); xS_tB)C  
} ;eP. B/N  
catch(Exception e) nDXy$f8  
{ Suk;##I  
e.printStackTrace (); |q 0iX2W  
} qO>A 6  
} vcSb:('  
MwWN;_#EO)  
//日志 NZuylQ)0  
public static void log(String sMsg) ":L d}~>  
{ Ar`U / %Cu  
System.err.println(sMsg); BsYJIKfW  
} s+a#x(7{  
tS[@?qP  
1pTQMf a  
public static void log(int sMsg) J!iK W  
{ 8-)@q|  
System.err.println(sMsg); }QJ6"s  
} sDXQ{*6a  
} D#11 N^-K  
|k)Nf+(}W  
k'K 1zUBj  
/* }Q_ }c9?  
**TestMethod.java ;uqi  
*/ - S%8  
package NetFox; { ?]&P  
l6-%)6u>  
j8?rMD~  
public class TestMethod { Ki%RSW(_`  
OZno 3Hn  
xOc&n0}%  
public TestMethod() DC=XPn/V  
{ ///xx/weblogic60b2_win.exe &DWSu`z  
try{ C 4\Q8uK  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CoM?cS S  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9j$J}=y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {Lvta4}7(  
fileFetch.start(); D__*?frWpW  
} {y|j**NZ  
catch(Exception e){e.printStackTrace ();} n)rSgzI  
G\ /L.T  
trL8oZ6  
} Pol c.  
"XKd#ncP  
kj!mgu#T  
public static void main(String[] args) nPjN\Es6  
{ <nF1f(ky  
new TestMethod(); &=l aZxe  
} UvVq#<-  
} f/g-b]0  
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