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http断点续传简单实现(java)

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/* _=f=fcl  
**SiteFileFetch.java UXr5aZ7y  
*/ DT(d@upH  
package NetFox; " {de k  
import java.io.*; #CUz uk&  
import java.net.*; QV|>4^1D  
1+kE!2b;b  
mqtg[~dNc  
public class SiteFileFetch extends Thread { s}5+3f$f  
uXZg1 F)  
[3/VCYje  
SiteInfoBean siteInfoBean = null; //文件信息Bean wFS2P+e;X  
long[] nStartPos; //开始位置 - xm{&0e)  
long[] nEndPos; //结束位置 dbdM"z 4  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 $hrIO+  
long nFileLength; //文件长度 c WAtju?L;  
boolean bFirst = true; //是否第一次取文件 S7iDTG_@t  
boolean bStop = false; //停止标志 </zXA$m  
File tmpFile; //文件下载的临时信息 #& .]" d  
DataOutputStream output; //输出到文件的输出流 &p(0K4:  
wVl+]zB  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) GC@+V|u  
public SiteFileFetch(SiteInfoBean bean) throws IOException =6 r:A<F!n  
{ 7N8H)X  
siteInfoBean = bean; J1ON,&[J  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); BzJ;%ywS  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); A&5:ATQ/|  
if(tmpFile.exists ()) 5N7H{vT_  
{ D/(CU#i"  
bFirst = false; *#U+qgA;`  
read_nPos(); _c(4o:  
} f{#j6wZM  
else PA;6$vqX  
{ {d3<W N  
nStartPos = new long[bean.getNSplitter()]; vXj<  
nEndPos = new long[bean.getNSplitter()]; "j<bA8$Vw  
} ,yMU@Vg  
1eS_ nLFw~  
n]Li->1  
_Q(g(p&  
} G%l u28}D  
$0A~uDbs  
E;Y;r"  
public void run() 62'1X"  
{ yl&UM qI(  
//获得文件长度 _`-1aA&n~  
//分割文件 l1=JrpCan  
//实例FileSplitterFetch d' >>E  
//启动FileSplitterFetch线程 px''.8   
//等待子线程返回 ,YYVj{~2  
try{ 2{,n_w?Wy  
if(bFirst) 9SQ4cv*2  
{ @p=AWi}\  
nFileLength = getFileSize(); ShOX<Fb&  
if(nFileLength == -1) T(?HMyg3  
{ bO5k6i  
System.err.println("File Length is not known!"); w(d>HHg  
} L5YnG_M&  
else if(nFileLength == -2) Mz]: }qmFA  
{ 5sO@OV\ y  
System.err.println("File is not access!");  cgu~  
} h@{_duu  
else GwU?wIIj^  
{ 9O*_L:4o  
for(int i=0;i<nStartPos.length;i++) 8|?LN8rp  
{ &^&zR(o`  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); +UN<Zp7I/  
} ,3i,P(?(  
for(int i=0;i<nEndPos.length-1;i++) Y.#:HRtgW  
{ p,g1eb|E  
nEndPos = nStartPos[i+1]; ^L4Qbc(vJ  
} a,t``'c;  
nEndPos[nEndPos.length-1] = nFileLength; bvBHYf:^  
} wN-i?Ek0;  
} nz.{P@[Qk  
^D^JzEy'?C  
revF;l6->C  
//启动子线程 %^. %OCX:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yL4 T  
for(int i=0;i<nStartPos.length;i++) |R/.r_x,V?  
{ d)o!5L  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ck =;1sGh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B$Z3+$hfF  
nStartPos,nEndPos,i); P,DC7\  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T'-FV  
fileSplitterFetch.start(); "t=hzn"~%  
} Joe_PS  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :G w~7v_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >ydRSr^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hg@}@Wq\)  
nEndPos = " + nFileLength); 3 voT^o  
// fileSplitterFetch[nPos.length-1].start(); d&8APe  
tMx}*l|]  
Q;Wj?8}  
//等待子线程结束 [Qt?W gPj  
//int count = 0; #L}+H!Myh  
//是否结束while循环 V D?*h  
boolean breakWhile = false; Uh1NO&i.W  
?']h%'Q  
F1%vtk;2?  
while(!bStop) =QJRMF  
{ DaHZ{T8>d  
write_nPos(); -D^A:}$  
Utility.sleep(500); J<gJc*Q  
breakWhile = true; 98jN)Nl,oD  
)2q~u%9n  
x"P);su  
for(int i=0;i<nStartPos.length;i++) \vfBrN  
{ gwd (N  
if(!fileSplitterFetch.bDownOver) nP~({ :l8X  
{ `IpA.| Y  
breakWhile = false; IxR?'  
break; 1'v5/   
} =VLS/\A  
} {Hmo1|_S|  
if(breakWhile) yqXH:757~  
break; \'CN  
DmVP  
GV6K/T :  
//count++; 3l<S}k@M)  
//if(count>4) pg+[y<B  
// siteStop(); wu9=N ^x  
} o'<^LYSnB  
*1Z5+uVT[  
~9\WFF/  
System.err.println("文件下载结束!"); S\6[EQ65  
} i|)Su4Dw  
catch(Exception e){e.printStackTrace ();} 6&Juv  
} 5m:i6,4  
RyB~Lm`ZK%  
X;F?:Iw\  
//获得文件长度 dUznxZB  
public long getFileSize() V}o n|A  
{ 39F O f  
int nFileLength = -1; ^taBG3P  
try{ OU4pjiLx  
URL url = new URL(siteInfoBean.getSSiteURL()); ,vqr <H9e  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d1@%W;qX!  
httpConnection.setRequestProperty("User-Agent","NetFox"); v4miU;|\  
EVX{ 7%  
vKwQXR~C  
int responseCode=httpConnection.getResponseCode();  =$8nUX`  
if(responseCode>=400) wv QMnE8\  
{ Xd E`d.  
processErrorCode(responseCode); r,goRK.  
return -2; //-2 represent access is error Hd7,ZHj3 ^  
} I2$T"K:eo  
$GQ`clj<  
_sE#)@p  
String sHeader; @;xMs8@  
yL^UE=#C_  
LLWB  
for(int i=1;;i++) C'=k&#<-  
{ &0TVi  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +bK.NcS  
//Utility.log(in.readLine()); rKHY?{!  
sHeader=httpConnection.getHeaderFieldKey(i); cH-@V<  
if(sHeader!=null) 'Djm0  
{ ~1m2#>  
if(sHeader.equals("Content-Length")) b?4/#&z]  
{ e6X[vc|Y}  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XS0xLt=  
break; O<)y-nx;X  
} ``,k5!a66\  
} ^[Ua46/"m  
else ._wkj  
break; 9%ii '{  
} O?8Ni=]  
} &~UJf4b|A  
catch(IOException e){e.printStackTrace ();} 8;y&Pb~)  
catch(Exception e){e.printStackTrace ();} p2J|Hl|  
G1t\Q-|l0  
N$Y" c*  
Utility.log(nFileLength); wi8Yl1p]!z  
[>#*B9  
HIGq%m=-x  
return nFileLength; ]Mj/&b>"e  
} sG~<M"znV  
[U#72+K  
-IlJ^Al4  
//保存下载信息(文件指针位置) "'^4*o9  
private void write_nPos() kVI#(uO  
{ n\I#CH0V  
try{ 7@.cOB`y@3  
output = new DataOutputStream(new FileOutputStream(tmpFile)); }7{t^>;D  
output.writeInt(nStartPos.length); H4OhIxK  
for(int i=0;i<nStartPos.length;i++) T9 <2A1  
{ ,U*)2`[  
// output.writeLong(nPos); :RSz4  
output.writeLong(fileSplitterFetch.nStartPos); \^1+U JU  
output.writeLong(fileSplitterFetch.nEndPos); zPEg  
} krq/7|  
output.close(); sfr(/mp(  
} 'B83m#HR#  
catch(IOException e){e.printStackTrace ();} 3:"]Rn([P  
catch(Exception e){e.printStackTrace ();} #tt?!\8C  
} TGuiNobD  
t3Z_Dp~\  
b1pQ`qt  
//读取保存的下载信息(文件指针位置) S1n3(U:m  
private void read_nPos() 6#}93Dgv4  
{ ` b !5^W  
try{ +^rh[>W  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ERUt'1F?]  
int nCount = input.readInt(); Nf+b" &Zh`  
nStartPos = new long[nCount]; 0.r4f'vk  
nEndPos = new long[nCount]; f:zFFpP.j@  
for(int i=0;i<nStartPos.length;i++) 7;.xc{  
{ Bhqft;Nuh  
nStartPos = input.readLong(); X.ONa_  
nEndPos = input.readLong(); QQk{\ PV  
} :J}t&t  
input.close(); \&V0vN1  
} [=uo1%  
catch(IOException e){e.printStackTrace ();} zJa)*N  
catch(Exception e){e.printStackTrace ();} %zC[KE*~  
} ?%R w(E  
F Kc;W  
2y0J`!/)  
private void processErrorCode(int nErrorCode) kH*Pn'  
{ zWw2V}U!  
System.err.println("Error Code : " + nErrorCode); aYL|@R5;e  
} 6Dws,_UAZ4  
RO\gax  
"`}~~.q  
//停止文件下载 QVZD/shq  
public void siteStop() 7Y=cn_ wU  
{ r#WT`pav  
bStop = true; k.h`Cji@  
for(int i=0;i<nStartPos.length;i++) 78n=nHS  
fileSplitterFetch.splitterStop(); IWVlrGyM  
< (RC|?  
"_L?2ta  
} W]<$0  
} ?wMHS4  
//负责部分文件的抓取 kI*(V [i  
**FileSplitterFetch.java Xog/O i  
*/ hovGQHg  
package NetFox; :/YO ni1h  
G@!z$  
y$ Zj?Dd#  
import java.io.*; sK$wN4k  
import java.net.*; mIZwAKo  
VvByHcLv  
u#W5`sl  
public class FileSplitterFetch extends Thread { 71FeDpe  
\a "Ct'  
GYRYbiwqdi  
String sURL; //File URL ?{o/I\\  
long nStartPos; //File Snippet Start Position [}nK"4T"Ri  
long nEndPos; //File Snippet End Position {hSGv   
int nThreadID; //Thread's ID Gtv,Izt  
boolean bDownOver = false; //Downing is over >(9F  
boolean bStop = false; //Stop identical v=Y K8fNi  
FileAccessI fileAccessI = null; //File Access interface 5`^o1nGO'  
[c K^+s)N  
U3;aLQ*  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I"L;L?\S  
{  }`/gX=91  
this.sURL = sURL; #~:P}<h  
this.nStartPos = nStart; V|Tud  
this.nEndPos = nEnd; BJjx|VA+  
nThreadID = id; W@L3+4  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8$P>wCK\l  
} 33l>{(y  
KV!<Oq  
YZ#V#[j'^  
public void run() db=$zIB[:  
{ 9pWy"h$H  
while(nStartPos < nEndPos && !bStop) 0V,Nv9!S  
{ <~Q i67I  
MKGS`X]<J  
UgHf*m  
try{ $FM' 3%B[  
URL url = new URL(sURL); HP2wtN{Zs  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E +_&HG}a  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8Vl!|\x5  
String sProperty = "bytes="+nStartPos+"-"; $j` $[tX6l  
httpConnection.setRequestProperty("RANGE",sProperty); Aw ^yH+ae  
Utility.log(sProperty); ZwI 1* f  
#5CI)4x0!  
A;K(J4y*  
InputStream input = httpConnection.getInputStream(); >O{7/)gS^  
//logResponseHead(httpConnection); 8m=Z|"H@  
F%.xuLW  
HB& &  
byte[] b = new byte[1024]; uF(k[[qaiN  
int nRead; g#^|oYuH6  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I@7/jUO  
{ M8W#io  
nStartPos += fileAccessI.write(b,0,nRead); wvc>0?t'  
//if(nThreadID == 1)   -/{af  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,TC~~EWq  
} t\y-T$\\  
E{^^^"z P  
_g|acBF  
Utility.log("Thread " + nThreadID + " is over!"); h* .w"JO  
bDownOver = true; ;_JH:}j  
//nPos = fileAccessI.write (b,0,nRead); s${_K*g6  
} OD9 yxN>P  
catch(Exception e){e.printStackTrace ();} 4rB8Nm1  
} e1 a*'T$z  
} +cg {[f,J;  
D5A=,\uk  
hY;_/!_  
//打印回应的头信息 r2eQ{u{nX  
public void logResponseHead(HttpURLConnection con) Pn WD}'0V  
{ bkQ3c-C<  
for(int i=1;;i++) pG yRX_;  
{ }C6@c1myq-  
String header=con.getHeaderFieldKey(i); Q7Ij4  
if(header!=null) c?6d2jH.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q_P5MLU>  
Utility.log(header+" : "+con.getHeaderField(header)); (aKZ5>>cN  
else `F1dyf!p<  
break; oh\,OW  
} -CBD|fo[h  
} !oMt_k X  
uEd,rEB>  
jXIEp01  
public void splitterStop() = HE m)  
{ &4kM8Qh  
bStop = true; R2^iSl%pj  
} k/`i6%F#m  
pCt}66k}  
m^tNqJs8  
} ~mH+DV3  
31XU7A  
olty4kGD$V  
/* S<oQ}+4[~  
**FileAccess.java iHz[Zw^.s  
*//文件访问(定位,写) hx!`F  
package NetFox; N lt4)  
import java.io.*; "{F;M{h$},  
.hN3`>*V  
!<Z{@7oH  
public class FileAccessI implements Serializable{ YNM\pX'  
8~5|KO >F  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S}gD,7@  
RandomAccessFile oSavedFile; 3?ba 1F0Nw  
long nPos; G[6=u|(M  
60PYCqWc  
BX$hAQ(6Q  
public FileAccessI() throws IOException |R~;&x:  
{ *i?.y*g  
this("",0); 6FjVmje  
} q<XcOc5  
7Po/_%  
s/ S+ ec3  
public FileAccessI(String sName,long nPos) throws IOException D8/sz`N7Q  
{ 4A~)b"j5  
oSavedFile = new RandomAccessFile(sName,"rw"); T46{*(  
this.nPos = nPos; f[@#7,2~M  
oSavedFile.seek(nPos); :&$Xe1)i]  
} "jGe^+9uT  
? ).(fP  
MZ^Ch   
public synchronized int write(byte[] b,int nStart,int nLen) E& ]_U$  
{ ^ wQcB  
int n = -1; r5)f82pQ  
try{ A_Gp&acs$  
oSavedFile.write(b,nStart,nLen); =g2\CIlVU6  
n = nLen; CjZ6NAHc  
} Kq6qXc\x  
catch(IOException e) AI fk"2  
{ M,{<TpCx  
e.printStackTrace (); 6QptKXu7  
} EG1x  
s}!"a8hU`  
*2:Yf7rvI+  
return n; *]9XDc]{j1  
} w{ m#Yt  
4H9xO[iM  
K z^hQd  
} h>Rpb#]  
)fR1n}#  
UJs?9]x>  
/* j)@oRWL<  
**SiteInfoBean.java 0C7"3l  
*/ +}]wLM}\UF  
package NetFox; @}{VM)Fc+  
I)uASfT$  
Y;PDZb K3  
public class SiteInfoBean { `R ]&F$i(E  
B)d@RAk  
9;:7e*x]lc  
private String sSiteURL; //Site's URL A>y#}^l]  
private String sFilePath; //Saved File's Path Oi#k:vq4  
private String sFileName; //Saved File's Name lc-*8eS  
private int nSplitter; //Count of Splited Downloading File fa.f(c  
L%4tw5*N  
C$0 ITw  
public SiteInfoBean() .?7So3   
{//nSplitter的缺省值为5 h@/>?Va  
//default value of nSplitter is 5 LQ|<3]  
this("","","",5); Ae3#>[]{  
} n]Ebwznt-  
-*5yY#fw}  
C890+(D~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @) ]t8(  
{ n7'<3t  
sSiteURL= sURL; |O^V)bZmx  
sFilePath = sPath;  pe|\'<>i  
sFileName = sName; akY6D]M  
this.nSplitter = nSpiltter; -hm 9sNox  
t"FRLC  
}8X:?S %  
} +0)5H>h  
{S# 5g2  
OQ 0b$qw  
public String getSSiteURL() $M%}Oz3*  
{ 2}1!WIin  
return sSiteURL; |oB]6VS`  
} [kQ"6wh8  
HJ(=?TU  
|O'Hh7  
public void setSSiteURL(String value) ec,z6v^9  
{ yA457'R1  
sSiteURL = value; @#J H=-06  
} Y-?51g[u  
;2 \<M 6  
gS0,')w  
public String getSFilePath() NdaM9a#TZ  
{ m}sh I8S  
return sFilePath; +._f.BRmX.  
} $::51#^Wg  
y0lLFe~  
SlM>";C\  
public void setSFilePath(String value) :1%VZvWk*  
{ puk4D  
sFilePath = value; _LLW{^V  
} *YMXiYJR  
YlxUx  
VN1# 8{  
public String getSFileName() LH1BZ(5g  
{ +X{cN5Y K  
return sFileName; +lW+H12  
} iOE9FW|e  
.kz(V5  
(p}9^Y  
public void setSFileName(String value) :a#|  
{ #zh6=.,7  
sFileName = value; GXGN;,7EV  
} dICnB:SSB  
)I^)*(}  
zV9 =  
public int getNSplitter() Ji)%Y5F  
{ P DNt4=C  
return nSplitter; vWZ>Hf]`L  
} _ +u sn.  
1KNkl,E  
|Sy}d[VKsZ  
public void setNSplitter(int nCount) +<vqkc  
{ )@?Qt2  
nSplitter = nCount; bUpmU/ RW  
} f4qS OVv  
} w`w ` q'  
\f ~u85  
?^F*"+qI  
/*  'lSnyW{  
**Utility.java %> oT7|x  
*/ U<#$w{d:  
package NetFox; hA$c.jJr.Z  
Vw6>:l<+<  
y?rK5Yos  
public class Utility { T(t <Ay?c  
[0( E>vm  
{3_Ffsg`  
public Utility() j@!BOL~?  
{ c9>8IW  
E0WrpGZ  
uk>q\j  
} KR+aY.  
4C2>0O<^s  
//线程睡眠 6Vu}k K)  
public static void sleep(int nSecond) hv_pb#1Ks  
{ g%KGF)+H  
try{ 5G dY7t_1  
Thread.sleep(nSecond); t\E-6u  
} @p?b"?QaB  
catch(Exception e) 3(XHF3q  
{ [v>Z(  
e.printStackTrace (); Al;%u0]5  
} Q)7L^  
} {g23[$X]N  
I{Y {  
//日志 kM}ic(K  
public static void log(String sMsg) Z:r$;`K/  
{ kfG65aa>_  
System.err.println(sMsg); N23+1h  
} B[2h   
I=3B 5u  
".Q!8j"@f  
public static void log(int sMsg) 'IqK M  
{ (PE8H~d  
System.err.println(sMsg); d[qEP6B  
} %s&E-*X  
} &,6y(-  
t8a@L(J$  
UH.}B3H   
/* @pEO@bbg>  
**TestMethod.java EzeDShN=J  
*/ 9cx!N,R t  
package NetFox; GwU>o:g"  
vb80J<4  
d%[`=fs]|m  
public class TestMethod { n+A'XBHk  
!EyGJa[ i  
8M(|{~~3:  
public TestMethod() is _ dPc  
{ ///xx/weblogic60b2_win.exe Q'%5"&XFD  
try{ Ot8S'cB1,$  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %o _0M^3W  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CzDR%vx  
SiteFileFetch fileFetch = new SiteFileFetch(bean); V+@%(x@D_  
fileFetch.start(); 6=`m   
} kxKnmB#m-  
catch(Exception e){e.printStackTrace ();} ytcG6WN3  
Ty,)mx){)  
_|5FrN  
} ~_^o?NE,  
Yqz[sz5+m  
Z2pN<S{5  
public static void main(String[] args) \w@_(4")Qb  
{ Rs( CrB/M  
new TestMethod(); H--*[3".  
} # |*,zIYo  
} Qi'WV9ke  
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