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http断点续传简单实现(java)

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/* 69#mj*p@+  
**SiteFileFetch.java n0|oV(0FE  
*/ %04N"^mT'~  
package NetFox; K_/-mwA v  
import java.io.*; Ik[aiz  
import java.net.*; 9G njJ  
Yq~$Q4  
*12,MO>go  
public class SiteFileFetch extends Thread { UjCQ W:[  
P<<?7_ ??  
.|>zQ(7YC  
SiteInfoBean siteInfoBean = null; //文件信息Bean mocR_3=Q?  
long[] nStartPos; //开始位置 CjtBQ5  
long[] nEndPos; //结束位置 #4hxbRN  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 tA#7Xr+  
long nFileLength; //文件长度 5f5bhBZ<  
boolean bFirst = true; //是否第一次取文件 ,/{(8hn  
boolean bStop = false; //停止标志 +?"N5%a%F  
File tmpFile; //文件下载的临时信息 .Up\ 0|b  
DataOutputStream output; //输出到文件的输出流 u,h,;'J  
Ns?qLSN  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Xvy3D@o  
public SiteFileFetch(SiteInfoBean bean) throws IOException mOiA}BGw  
{ Rb!|2h)  
siteInfoBean = bean; 5]C}044  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); TNwBnMe  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); jUny&Alj  
if(tmpFile.exists ()) &T7|f!y  
{ =Xwr*FTr  
bFirst = false; DH7B4P  
read_nPos(); _i@{:v  
} S b0p?  
else pPI'0x  
{ sK1YmB :~a  
nStartPos = new long[bean.getNSplitter()]; >%qk2h>  
nEndPos = new long[bean.getNSplitter()]; D,cGW,2Nv  
} 8sMDe'  
eN*=wOh  
$raxf80A  
)8BGN'jyi  
} %V40I{1  
c eH8  
BGk>:Z`  
public void run() IZr~h9  
{ U[l7n3Y=  
//获得文件长度 PwF 1Pr`r  
//分割文件 <d2?A}<  
//实例FileSplitterFetch 4 h}03 oG  
//启动FileSplitterFetch线程 W6N3u7mrb  
//等待子线程返回 '. Ww*N  
try{ +w'"N  
if(bFirst) !_zp'V]?  
{ m8Wv46%  
nFileLength = getFileSize(); ~|W0+&):  
if(nFileLength == -1) $!~R'N c  
{ !Q-h#']~L  
System.err.println("File Length is not known!"); V L^.7U  
} kzMul<>sl  
else if(nFileLength == -2) h6Femis  
{ /(/Z~J[  
System.err.println("File is not access!"); d! BQ%a  
} )Dg;W6  
else .Vohd@s9l  
{ 0?DD!H)&w  
for(int i=0;i<nStartPos.length;i++) 5AX AIPn)  
{ |I; tBqN{u  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); />wM#)o2  
} "6[a%f#Q  
for(int i=0;i<nEndPos.length-1;i++) )<J|kC\r6c  
{ j`fQN  
nEndPos = nStartPos[i+1]; ;m/h?Y~  
} KKrLF?rc  
nEndPos[nEndPos.length-1] = nFileLength; Z%h _g-C  
} A&HN7C%X  
} hDO\Q7  
L5+X&  
R`IFKmA EJ  
//启动子线程 &sFEe<  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; li!3bv  
for(int i=0;i<nStartPos.length;i++) iD;pXE{2s%  
{ 79DzrLu  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S5Hb9m&&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kTC'`xv  
nStartPos,nEndPos,i); :K:oH}4oh  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :htz]  
fileSplitterFetch.start(); bOEO2v'cQ  
} dC&OjBQ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6Kl%|VrJs  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \a_75^2  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e(e_p#  
nEndPos = " + nFileLength); F&tU^(7<  
// fileSplitterFetch[nPos.length-1].start(); Dd:TFZo  
]lX`[HX7  
xz$-_NWW  
//等待子线程结束 (-<s[VnXP  
//int count = 0; Y/%(4q*'  
//是否结束while循环 fX ^h O+f  
boolean breakWhile = false; .Yw  
\wJ2>Q  
iMT[s b  
while(!bStop) "aU) [  
{ fwkklg^  
write_nPos(); =:w]EpH"  
Utility.sleep(500); `Z#0kpXk_  
breakWhile = true; #9( 0.!v  
mJ_ 5Vt=  
m;_gNh8Ee  
for(int i=0;i<nStartPos.length;i++) \ oY/hT_  
{ 6KvoHo  
if(!fileSplitterFetch.bDownOver) wjq;9%eXk  
{ }@)r\t4m  
breakWhile = false; Li'>pQ+  
break; P{bRRn4Z  
} GiZv0>*x  
} Mr0<b?I  
if(breakWhile) <W>T!;4!  
break; D]?eRO9'  
f3>L/9[[<P  
y ;\m1o2  
//count++; 65HP9`5Tm  
//if(count>4) |;(95  
// siteStop(); Jw 4#u5$$Z  
} ^vj}  
s~z~9#G(6  
B~CdY}UTsj  
System.err.println("文件下载结束!"); & t.G4  
} \80W?9qj  
catch(Exception e){e.printStackTrace ();} r_x|2 A oO  
} /wR,P  
iBM;$0Y  
u~C,x3yr  
//获得文件长度 xg;o<y KF  
public long getFileSize() j`D%Wx_  
{ nrF5^eZ#  
int nFileLength = -1;  kS7`g A  
try{ QX`T-)T e  
URL url = new URL(siteInfoBean.getSSiteURL()); wv7XhY}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hZ[(Ik]*Zd  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ah?,9r=U  
S"@/F- 81  
>1$ vG  
int responseCode=httpConnection.getResponseCode(); :Rroz]*  
if(responseCode>=400) u_Wftb?9  
{ anzt;V.;Y  
processErrorCode(responseCode); #Q]^9/;|4n  
return -2; //-2 represent access is error NT0im%  
} nOCCOTf  
XkEJ_;:  
joRrsxFU  
String sHeader; +%~/~1  
q:/3uC7   
^[6S]Ft(  
for(int i=1;;i++) SWLt5dV  
{ ${F4x"x  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +F4SU(T  
//Utility.log(in.readLine()); q`0wG3  
sHeader=httpConnection.getHeaderFieldKey(i); -cONC9 =  
if(sHeader!=null) BN~gk~t_  
{ n/6qc3\5i  
if(sHeader.equals("Content-Length")) |>~pA}  
{ Yo*.? Mq'  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Xl %ax!/  
break; ?'IY0^  
}  Tb[1\  
} z[sP/{~z  
else k9_c<TSzu  
break; Ncr*F^J4  
} k0v&U@+-J  
} fe4Ki  
catch(IOException e){e.printStackTrace ();} TF %MO\!  
catch(Exception e){e.printStackTrace ();} ;{Nc9d  
V#,jUH|  
5hvg]w95;  
Utility.log(nFileLength); UOa n  
:pCv!g2  
=L]GQ=d  
return nFileLength; k^#+Wma7  
} {g]Mx|5Q  
XQPlhpcv  
U~GQ JR  
//保存下载信息(文件指针位置) )gHfbUYS  
private void write_nPos() )?MUUI:  
{ 0a}a  
try{ @~CXnc0  
output = new DataOutputStream(new FileOutputStream(tmpFile)); P;U(2;9 N  
output.writeInt(nStartPos.length); )Y &RMYy  
for(int i=0;i<nStartPos.length;i++) I /z`)  
{ GO]5~ 4k  
// output.writeLong(nPos); 5L y Wg2  
output.writeLong(fileSplitterFetch.nStartPos); v+vM:At4  
output.writeLong(fileSplitterFetch.nEndPos); i@L_[d^|j`  
} C0}@0c  
output.close(); 60#eTo?}o  
} >pm`(zLn  
catch(IOException e){e.printStackTrace ();} ~zYk,;m  
catch(Exception e){e.printStackTrace ();} sW&5Mu-  
} xl ]1TB@  
61W[  
1W'0h$5^"  
//读取保存的下载信息(文件指针位置) @h,3"2W{Ev  
private void read_nPos() WD>z  
{ 80%L!x|  
try{ e X{#F gFc  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]ne  
int nCount = input.readInt(); isU4D  
nStartPos = new long[nCount]; (b8ZADI*  
nEndPos = new long[nCount]; :pdl2#5H^  
for(int i=0;i<nStartPos.length;i++) 85_Qb2<'r  
{ (3?W) i  
nStartPos = input.readLong(); n.7-$1  
nEndPos = input.readLong(); &&ZX<wOM  
} rlQ=rNrG&E  
input.close(); )Ah7  
} 5ENEx  
catch(IOException e){e.printStackTrace ();} ~X<?&;6  
catch(Exception e){e.printStackTrace ();} FWW*f _L  
} d]K$0HY  
uH |:gF^  
P?hB`5X  
private void processErrorCode(int nErrorCode) uQYenCNXS  
{ K/0Wp %  
System.err.println("Error Code : " + nErrorCode); mRIBE9K+&  
} ;;K ~  
4+J>/ xiZ  
qH(HcsgD  
//停止文件下载 dC>(UDC  
public void siteStop() ,Bs/.htQj  
{ )I"I[jDw  
bStop = true; tu's]3RE  
for(int i=0;i<nStartPos.length;i++) abw5Gz@Ag  
fileSplitterFetch.splitterStop(); T|-llhJ8  
)fl+3!tq  
PJPKn0,W  
} DN;|?oNZ  
} ]Q#k"Je  
//负责部分文件的抓取 gKP=@v%-  
**FileSplitterFetch.java 8GeJ%^0o}  
*/ FEdFGT  
package NetFox; yRR[M@Y  
9v/=o`J#  
)|6OPR@(#/  
import java.io.*; H.< F6  
import java.net.*; @RHG@{x{K  
b(\Mi_J  
`R*SHy! _  
public class FileSplitterFetch extends Thread { "fC>]iA8I  
I2WWhsNC  
1<Vke$   
String sURL; //File URL q1Ad"rm  
long nStartPos; //File Snippet Start Position :{9HsF"h0  
long nEndPos; //File Snippet End Position z @?WhD  
int nThreadID; //Thread's ID *).!  
boolean bDownOver = false; //Downing is over P1^O0)  
boolean bStop = false; //Stop identical Q<Qd*v&-  
FileAccessI fileAccessI = null; //File Access interface _p'u!.a?!  
X>%li$9J.  
(>uA(#Z  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *i {e$Zv'  
{ e>x+Xj1  
this.sURL = sURL; J7HY(7Nx  
this.nStartPos = nStart; pV O{7I  
this.nEndPos = nEnd; t +|t/1s2  
nThreadID = id; s Fx0  
fileAccessI = new FileAccessI(sName,nStartPos);//定位  F*_+k  
} qJE_4/<^!  
Sx1|Oq]  
[ldBI3  
public void run() "m`}J*s"  
{ X\kWJQ:  
while(nStartPos < nEndPos && !bStop) 2BiFP||  
{ ZiPz~G0[^  
\Vpv78QF;  
 $Gcjm~  
try{ *z};&UsF{  
URL url = new URL(sURL); ]c M8TT  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kt |j]:  
httpConnection.setRequestProperty("User-Agent","NetFox"); `A#0If  
String sProperty = "bytes="+nStartPos+"-"; -2j[;kgt}  
httpConnection.setRequestProperty("RANGE",sProperty); s4j]kH  
Utility.log(sProperty); ?6UjD5NkX  
9&{z?*  
Vha,rIi  
InputStream input = httpConnection.getInputStream(); )q`.tsR>  
//logResponseHead(httpConnection); w3#0kl  
jOd+LXPJ  
u$FL(m4  
byte[] b = new byte[1024]; >7r%k,`  
int nRead; #/5eQTBD  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1bjz :^  
{ CF:L#r  
nStartPos += fileAccessI.write(b,0,nRead); _sn<"B%>  
//if(nThreadID == 1) jO9! :L>b`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nNeCi  
} ,~/WYw<o  
_ ^'QHWP  
ilyF1=bp  
Utility.log("Thread " + nThreadID + " is over!"); ?_r{G7|D  
bDownOver = true; G7i0P j  
//nPos = fileAccessI.write (b,0,nRead); N)PkE>%X  
} 9z`72(  
catch(Exception e){e.printStackTrace ();} .<Ays?  
} ]L2b|a3  
} !MVf(y$  
x.$cP  
ttls.~DG  
//打印回应的头信息 wp83E,  
public void logResponseHead(HttpURLConnection con) Bw~jqDZ}|  
{ L9oLdWa(C  
for(int i=1;;i++) 6&QOC9JW+7  
{ Lq2jXy5#n  
String header=con.getHeaderFieldKey(i); `q`ah_  
if(header!=null) zG{jRth  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i'.D=o  
Utility.log(header+" : "+con.getHeaderField(header)); XMz*}B6GQ  
else ?XeaoD/  
break; !pC`vZG"  
} j#u{(W'r  
} YkE_7r(1  
#^yOW^  
4|\  
public void splitterStop() x$t2Y<_  
{ *3]2vq  
bStop = true; Kz z/]  
} l-Ha*>gX[j  
UFLx'VX d  
`PUxR8y  
} s}-j.jzB{  
$j8CF3d.6  
fP6\Ur  
/* =M}tet }  
**FileAccess.java It<VjN9  
*//文件访问(定位,写) bxzx@sF2l  
package NetFox; HAo=t  
import java.io.*; 'nq~1 >i  
f96`n+>x i  
Qv g_|~n  
public class FileAccessI implements Serializable{ V7`vLs-  
sAPQbTSM  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R NQq"c\  
RandomAccessFile oSavedFile; :I2,  
long nPos; \B:k|Pw6~  
We\i0zUU  
s:iBl/N}  
public FileAccessI() throws IOException c`&g.s@N\  
{ R4T@ ]l&W  
this("",0); bg/=P>2  
} P{BW^kAdH  
D?UURURf  
E 0l&d  
public FileAccessI(String sName,long nPos) throws IOException x^ `IZ{!  
{ !* KQ2#e  
oSavedFile = new RandomAccessFile(sName,"rw"); Jw#7b[a  
this.nPos = nPos; Ujlbcv6+  
oSavedFile.seek(nPos); ~H:=p  
} Om;aE1sW  
N8k=c3|  
V#|/\-@  
public synchronized int write(byte[] b,int nStart,int nLen) GY.iCub  
{ &}0QnO_mj  
int n = -1; |@d}O8  
try{ =HJ7tele  
oSavedFile.write(b,nStart,nLen); x%9Ca)r?}  
n = nLen; 7&/1K%x9;  
} }s:3_9mE  
catch(IOException e) *4LRdLMn  
{ O*bzp-6\  
e.printStackTrace (); 5`$!s17  
} XA(.O|VZ  
 (:o:_U  
b|@zjh;]A7  
return n; ZHUW1:qs  
} /R?[/`)f&  
`rK@> -  
hOkn@F.  
} bfEH>pQ>#  
$7]?P;$  
U;*t5l  
/* sDR Av%w  
**SiteInfoBean.java YJ-<t6  
*/ <Rs$d0/  
package NetFox; fI2 y(p{?  
hoM%|,0  
3 {hUp81>  
public class SiteInfoBean { Fw{68ggk  
8SL E*c^8  
n*' :,m  
private String sSiteURL; //Site's URL u 8<[Q]5  
private String sFilePath; //Saved File's Path m #G,m  
private String sFileName; //Saved File's Name ssS"X@VZ \  
private int nSplitter; //Count of Splited Downloading File 08{^Ksg  
-;ra(L`  
r}sO},i  
public SiteInfoBean() ?'|GGtvm  
{//nSplitter的缺省值为5 c HR*.  
//default value of nSplitter is 5 JiO8 EIM  
this("","","",5); <;'{Tj-"  
} wq,&0P-v  
7cWeB5 e?O  
[i.c;'Wy/  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W`c$2KS?DO  
{ N 3O!8A_  
sSiteURL= sURL; _?y3&4N)  
sFilePath = sPath; |Kjfh};-C  
sFileName = sName; 8B-mZFXpK  
this.nSplitter = nSpiltter;  qT #=C'?  
ZXkrFA |  
 - US>].  
} H3vnc\d~  
2xiE#l-V2  
B2*>7 kc_s  
public String getSSiteURL() 3Nwix_&S  
{ =qoOr~  
return sSiteURL; zHg=K /  
} 7HY8 F5Brx  
w|6?A-  
|'JN<?   
public void setSSiteURL(String value) b/JjA  
{ e6H}L:;  
sSiteURL = value; 4p+Veo6B  
} i%F2^R@!q/  
Csp$_uDi  
\,n X/f  
public String getSFilePath() EE|c@M^  
{ ;$1x_ Cb  
return sFilePath; 2A =Y  
} X[dH*PV  
^!i4d))  
-{J0~1'#-  
public void setSFilePath(String value) ?~T(Cue>  
{ /*BK6hc  
sFilePath = value; %Ie,J5g5  
} ]q4LN o  
ZREy I(_  
{Y=k`t,  
public String getSFileName() AZ^>osr  
{ Anpp`>}N  
return sFileName; 6I=xjgwvf  
} . XbDb  
8.^`~ta  
N?#L{Yt  
public void setSFileName(String value) Zn40NKYc  
{ }.U(Gxu$  
sFileName = value; 6(t'B!x  
} CS*lk!C  
[`E_/95  
[Mc Hl1a  
public int getNSplitter() H^`J(J+  
{ ])bgUH  
return nSplitter; } _];yw  
} f\=,_AQ  
ZAeJTCCk  
]9'F<T= $_  
public void setNSplitter(int nCount) N+5f.c+S-  
{ {R[V  
nSplitter = nCount; RhT:]  
} =h=-&DSA  
} `1Md1e:J  
sh0x<_  
Q%!xw(  
/* 7<(U`9W/q  
**Utility.java hH-!3S2'  
*/ 59:kL<;S-  
package NetFox; dD'KP4Io@  
BILZ XMf  
y?3u6q++  
public class Utility { ) k[XO  
\>EUa}%xn  
U UtS me  
public Utility() qz Hsqlof  
{ 4DP<)KX  
q3-cWfU  
9^C6ZgNS  
} LV0gw"  
;[g~h |{6  
//线程睡眠 &`>dY /Y  
public static void sleep(int nSecond) 'u%_Ab_H  
{ yDe*-N\'W  
try{ =*6frC~  
Thread.sleep(nSecond); JJM!pD\h  
} wa&:86~l?  
catch(Exception e) EL2z&  
{ Po\+zZjo  
e.printStackTrace (); B%))HLo'  
} (U.VCSn  
} ov\%*z2=  
673G6Nk  
//日志 :'fK`G 6  
public static void log(String sMsg) {+kWK;1  
{ L+lye Ir'  
System.err.println(sMsg); AGVipI #  
} aK,\e/Oo  
m{lS-DlRg  
g&ba]?[A  
public static void log(int sMsg) ^Ga_wJP8S  
{ TC:t!:  
System.err.println(sMsg); 4zBcq<R7  
} ;t@^Z_z,CR  
} d)$ seZB  
K #JO#  
{cw+kY]m4-  
/* eR3MU]zF  
**TestMethod.java ,d=Dicaz  
*/ b+CvA(*  
package NetFox; gKPqU@$*  
Zyz)`>cB  
iq 8Hq)I]  
public class TestMethod { *s2 C+@ef  
1'k,P;s  
=)Goip  
public TestMethod() : :/vDUDc  
{ ///xx/weblogic60b2_win.exe j{/wG::  
try{ =_2(S6~  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N$Tzxs  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @Hp=xC9V  
SiteFileFetch fileFetch = new SiteFileFetch(bean); + J}h  
fileFetch.start(); #so"p<7 R  
} %.{xo.`a[  
catch(Exception e){e.printStackTrace ();} |l?*' =  
k9&pX8#  
mT1Q7ta*P  
} n{c-3w.uD  
|B),N f|a  
'1 \UFz  
public static void main(String[] args) q }9n.  
{ G)9`Qn  
new TestMethod(); T=pKen/  
} 2&F  H8  
} uv7tbI"r  
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