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http断点续传简单实现(java)

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/* LmJjO:W}^y  
**SiteFileFetch.java 2?%*UxcO  
*/ &6CDIxH{  
package NetFox; A[m?^vk q  
import java.io.*; \2 DED  
import java.net.*; Ne+Rs+~4  
\m|5Aqs  
vxPE=!|  
public class SiteFileFetch extends Thread {  it H  
@I4HpY7:  
F'[Y.tA ,#  
SiteInfoBean siteInfoBean = null; //文件信息Bean LAc60^t1  
long[] nStartPos; //开始位置 u_WUJ_  
long[] nEndPos; //结束位置 E|;>!MMA;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Fxa{ 9'99  
long nFileLength; //文件长度 ,|RKM  
boolean bFirst = true; //是否第一次取文件 i}8OaX3x  
boolean bStop = false; //停止标志 poafGoH-Y  
File tmpFile; //文件下载的临时信息 E'{:HX  
DataOutputStream output; //输出到文件的输出流 uB"B{:Kz  
.>;??BG}  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) W^3 Jg2gE  
public SiteFileFetch(SiteInfoBean bean) throws IOException \"ogQnmz  
{ q0%QMut%  
siteInfoBean = bean; Pxf>=kY  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =M?+KbTJ3  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); }R+#>P  
if(tmpFile.exists ()) Z#u{th  
{ q'S[TFMNE  
bFirst = false; $)*qoV  
read_nPos(); A v>v\ :.>  
} | t:UpP  
else uSXnf  
{ 3_wR2AU~  
nStartPos = new long[bean.getNSplitter()]; u^SInanw  
nEndPos = new long[bean.getNSplitter()]; ^/?7hbr  
} 8zMGpY#  
rEp\ld  
R(0[bMr3Q  
*P\lzM  
} mQVlE__ub  
,1 H|{<  
O+mEE>:w%  
public void run() / :.I&^>P  
{ *Jcd_D\-(1  
//获得文件长度 2|?U%YrHWs  
//分割文件 IY.M#Q ]  
//实例FileSplitterFetch }f;TG:6  
//启动FileSplitterFetch线程 /Zs_G=\>  
//等待子线程返回 p}==aNZK  
try{ "a;$uW@.6  
if(bFirst) 7@ONCG  
{ S ^~"#   
nFileLength = getFileSize(); , SUx!o  
if(nFileLength == -1) 7)D[}UXz  
{ b' ^<0c  
System.err.println("File Length is not known!"); E2}X[EoBF  
} &&$*MHJ  
else if(nFileLength == -2) 3-{WFnA  
{ Hj`'4  
System.err.println("File is not access!"); 9?sY!gXc  
} p/0dtnXa(  
else sE]z.Po=  
{ :KC]1_zqR  
for(int i=0;i<nStartPos.length;i++) x Y$x= )  
{ mW)kWuOO  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 3BK 8{/  
} >P(.yQ8&kL  
for(int i=0;i<nEndPos.length-1;i++) /Cwwz  
{ jHT^I as  
nEndPos = nStartPos[i+1]; U7U&^s6`  
} v" #8^q  
nEndPos[nEndPos.length-1] = nFileLength; ]Rf$&7`g{  
} F&p42!"  
} 3`D*AFQc  
eCJtNPd  
<}&J|()  
//启动子线程 !b0A %1W;  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w$s6NBF7  
for(int i=0;i<nStartPos.length;i++) gZ>&cju  
{ 9`qw,X&AK_  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WllQM,h  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p:tp |/  
nStartPos,nEndPos,i); 9:%')M&Q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i\ 7JQZ  
fileSplitterFetch.start(); cfBl HeYE  
} u-.5rH l  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q>X1 :Zn3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pdN8 hJ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zO9WqP_`iR  
nEndPos = " + nFileLength); dw}ge,bBic  
// fileSplitterFetch[nPos.length-1].start(); Tl"r#  
oEZhKVyc.y  
J7WNgl% u  
//等待子线程结束 KX\=wFbP)  
//int count = 0; /!5cf;kl*l  
//是否结束while循环 m_  wvi  
boolean breakWhile = false; r;(^]Soz  
OJydt;a  
StNA(+rT  
while(!bStop) &!:mL],  
{ 0%rE*h9+  
write_nPos(); wmbG$T%k  
Utility.sleep(500); Mf5*Wjz.Mc  
breakWhile = true; 4Af7x6a;  
s 64@<oU<"  
&`!H1E^  
for(int i=0;i<nStartPos.length;i++) \ D>!&   
{ x^`P[>  
if(!fileSplitterFetch.bDownOver) LCIe1P2  
{ USgO`l\}4  
breakWhile = false; UY *Z`$  
break; #Wl9[W/4  
} 'g<FL`iP  
} AKLFUk  
if(breakWhile) Y!c7P,cZ+3  
break; b,ZBol|X  
FFVh~em{  
lUnC+w#[  
//count++; LChwHkRHJI  
//if(count>4) ?: vB_@  
// siteStop(); r<dvo%I#|  
} ^5!"[RB\  
W^,p2  
4e[ 0.2?  
System.err.println("文件下载结束!"); _w <6o<@  
} w2!5TKZ`  
catch(Exception e){e.printStackTrace ();} =td(}3|D Y  
} BG-nf1K(  
Y)S f;  
QUXr#!rPY|  
//获得文件长度 ?ODBW/{[G  
public long getFileSize() M@. 2b.  
{ ygV-Fv>PQ  
int nFileLength = -1; S[/D._5QD%  
try{ DoeE=X*`k  
URL url = new URL(siteInfoBean.getSSiteURL()); <c(%xh46  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1X&scVw  
httpConnection.setRequestProperty("User-Agent","NetFox"); m aQDD*  
rc{F17~vX  
]K5j(1EN  
int responseCode=httpConnection.getResponseCode(); 68qCY  
if(responseCode>=400) V22Br#+  
{ f0{ tBD!%  
processErrorCode(responseCode); bC&xN@4  
return -2; //-2 represent access is error d$MewDW UN  
} u]3VK  
i#U_g:~wC  
d\ 7OtM  
String sHeader; 8f&#WIZ  
uF*tlaV6  
%yVP@M  
for(int i=1;;i++) ]>(pQD  
{ kI*f}3)Y  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SV1;[  
//Utility.log(in.readLine()); kkT=g^D9j  
sHeader=httpConnection.getHeaderFieldKey(i); t/x]vCP,2D  
if(sHeader!=null) :WSszak  
{ 5.Nc6$ N  
if(sHeader.equals("Content-Length")) #@uF?8u  
{ %SMP)4Y/R  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?+{qmqN  
break; 2 :^  
} f5CnJhE|)  
} =~$)Ieu  
else GtqA@&5&  
break; c#[d7t8ONe  
} a&n}pnEn)  
} 9aKCO4  
catch(IOException e){e.printStackTrace ();} _ba.oIc  
catch(Exception e){e.printStackTrace ();} x@VZJrQQ  
N2EX`@_2  
PrEfJ?  
Utility.log(nFileLength); 2\xEMec  
tjDCfJx*  
KJ6:ZTbW  
return nFileLength; &K,rNH'R  
} 6~8X/ -02  
A0uA\E4q  
G9c2kX.Bf  
//保存下载信息(文件指针位置) +,0 :L :a  
private void write_nPos() -hO[^^i9  
{ ='.G,aJ9  
try{ -~=:tn)0  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Jy#2 1  
output.writeInt(nStartPos.length); NK(; -~{P  
for(int i=0;i<nStartPos.length;i++) YjeHNPf  
{ PKNpR  
// output.writeLong(nPos); Si[xyG6=  
output.writeLong(fileSplitterFetch.nStartPos); uI&<H T?  
output.writeLong(fileSplitterFetch.nEndPos); IlP@a[:_  
} 9Or  
output.close(); l:"zYcp%  
} (qy82F-|2  
catch(IOException e){e.printStackTrace ();} x4S0C[k  
catch(Exception e){e.printStackTrace ();} TSYe ~)I  
} a)M#O\i`  
rt!Uix&  
vqBT^Q_q;  
//读取保存的下载信息(文件指针位置) G2_l}q~  
private void read_nPos() kF"G {5  
{ O(44Dy@2  
try{ JclG*/Wjg4  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %-, -:e  
int nCount = input.readInt(); ~]lVixr9  
nStartPos = new long[nCount]; 8`  f=E h  
nEndPos = new long[nCount]; ew6\Z$1c~  
for(int i=0;i<nStartPos.length;i++) .Vb\f  
{ 2/G`ej!*  
nStartPos = input.readLong(); \}}) U#   
nEndPos = input.readLong(); vWpkU<&3|  
} A/U,|  
input.close(); ?Kf?Z`9 *Y  
} "0A !fRI~  
catch(IOException e){e.printStackTrace ();} ;1woTAuD  
catch(Exception e){e.printStackTrace ();} wWUt44:0O  
} P}C;%KzA  
y@Ga9bI7  
YumHECej  
private void processErrorCode(int nErrorCode) tcS7 @^'  
{ x[H9<&)D  
System.err.println("Error Code : " + nErrorCode); r081.<  
} w 7 j hS  
>Sh"/3%q  
6):^m{RH^  
//停止文件下载 {nlqQ.jO  
public void siteStop() OBmmOswg~  
{ +zLh<q0  
bStop = true; h4dT N}  
for(int i=0;i<nStartPos.length;i++) k'$UA$2d  
fileSplitterFetch.splitterStop(); `}9jvR5  
h\qM5Qx+Q  
T*sB Wn'am  
} )\r;|DN  
} Z3]ut #`  
//负责部分文件的抓取 ~Uw<E:?v  
**FileSplitterFetch.java ~$3X>?Q  
*/ `(7HFq<N  
package NetFox; cu V}<3&  
8HymkL&F  
aI0}E O  
import java.io.*; ^(8(z@y  
import java.net.*; ~%o?J"y  
kdHP v=/U  
#4<Rs|K  
public class FileSplitterFetch extends Thread { m"Y|xvIA  
6~j.S "  
QX j4cg  
String sURL; //File URL &7\q1X&Rr  
long nStartPos; //File Snippet Start Position 3d|n\!1r  
long nEndPos; //File Snippet End Position :. ja~Q  
int nThreadID; //Thread's ID w;p!~o &  
boolean bDownOver = false; //Downing is over 0au\X$)Q  
boolean bStop = false; //Stop identical zg=F;^oZ<  
FileAccessI fileAccessI = null; //File Access interface 4uG:*0{Yx  
7VQk$im399  
WhHnF*I  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aD,(mw-7r  
{ h5?yrti  
this.sURL = sURL; +u:Q+PkM  
this.nStartPos = nStart; ,TAzJ  
this.nEndPos = nEnd; |P"p/iY  
nThreadID = id; z"C+r'39d=  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ` E2@GX+,  
} i; 3^vhbQ  
1Goju ey  
y-iuOzq4  
public void run() qs]7S^yw  
{ pkR+H|  
while(nStartPos < nEndPos && !bStop) C r~!N|(  
{ >=_Z\ wA  
P|Ojt I  
bQ" w%!  
try{ MQv2C@K9F  
URL url = new URL(sURL); Ux Yb[Nbc  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KF[P /cFI  
httpConnection.setRequestProperty("User-Agent","NetFox"); MH>CCT  
String sProperty = "bytes="+nStartPos+"-"; /J"U`/ {4  
httpConnection.setRequestProperty("RANGE",sProperty); [z1[4  
Utility.log(sProperty); `E),G;I  
.D`""up|{  
clZ jb  
InputStream input = httpConnection.getInputStream(); 0{P Rv./`  
//logResponseHead(httpConnection); p/a)vN+*x'  
V@xlm h,  
Nuw_,-h  
byte[] b = new byte[1024]; |oSx*Gh  
int nRead; 3 UBg"1IC  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |lijnfp  
{ : _>/Yd7-&  
nStartPos += fileAccessI.write(b,0,nRead); kR0d]"dr  
//if(nThreadID == 1) *$ihNX]YG  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?{ "_9g9  
} il \q{Y o  
*k(>Qsb "  
rN'')n/F  
Utility.log("Thread " + nThreadID + " is over!"); _O-ZII~  
bDownOver = true; E r6'Ig|U  
//nPos = fileAccessI.write (b,0,nRead); hYS*J908  
}  ?vgHu  
catch(Exception e){e.printStackTrace ();} :Z@!*F  
} 2<*DL 6  
} =jX'FNv#  
;c'9Xyl-  
4$+9Wv  
//打印回应的头信息 FBYA d@="2  
public void logResponseHead(HttpURLConnection con) 75t\= 6#  
{ M8 E8r  
for(int i=1;;i++) z#8d\X/  
{  ;Q;u^T`  
String header=con.getHeaderFieldKey(i); Q-X<zn  
if(header!=null) S1<mO-  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c8cV{}7Kb  
Utility.log(header+" : "+con.getHeaderField(header)); +@Oo)#V|.  
else fXPD^}?Ux4  
break; e7<//~W7W  
} =U6%Wdth  
} S0_#h)  
BTwLx-p9t  
m8q3Pp  
public void splitterStop() 9}{i8 <$=  
{ A d0dg2Gw  
bStop = true; Cc?BJ  
} )19As8rL/o  
B*+3A!{s  
idLysxN  
} ^ $M@yWX6  
\(PC#H%  
Xj/U~  
/* ^<8 c`k )e  
**FileAccess.java Dl kHE8r\  
*//文件访问(定位,写) (GVH#}uB  
package NetFox; =|lKB;  
import java.io.*; NzmVQ-4  
Fg3VD(D^U  
"JLKO${ Y  
public class FileAccessI implements Serializable{ .!ThqYo  
{ jnQoxN  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *^XfEO  
RandomAccessFile oSavedFile; "x. |'  
long nPos; LLn,pI2fL{  
KLI(Rve24  
'2u(fLq3h  
public FileAccessI() throws IOException xS) njuq4  
{ }t tiL  
this("",0); [TAW68f'  
} ,O@x v  
AnV\{A^  
h 7feZ_  
public FileAccessI(String sName,long nPos) throws IOException ]&za^%q0&  
{ a D*  
oSavedFile = new RandomAccessFile(sName,"rw"); nR7 usL  
this.nPos = nPos; /P~@__XN  
oSavedFile.seek(nPos); sN^3bfi!i  
} &+?JY|u  
@(Mg>.P  
stDrF1{  
public synchronized int write(byte[] b,int nStart,int nLen) fUh7PF%  
{ D"WqJcDt  
int n = -1; ,?"cKdiZ  
try{ pKf]&?FX  
oSavedFile.write(b,nStart,nLen); 1]HEwTT/1_  
n = nLen; FE+Y#  
} 6&p I{  
catch(IOException e) V6.xp{[  
{ 3:Aw.-,i\  
e.printStackTrace (); IL?mt2IQ>  
} \#P>k;D  
 D(}w$hi8  
D];%Ey  
return n; ,6,sz]3-  
} 3/P# 2&jt  
,EyZ2`|  
#rL%K3'  
} KdT1Nb=  
MP|J 0=H5  
(9_~R^='y  
/* cqzd9L6=  
**SiteInfoBean.java ~f&lQN'1  
*/ OI3UC=G  
package NetFox; L&wJ-}'l  
0f.rjd  
d\Xi1&&  
public class SiteInfoBean { rlEp&"+|M  
yUb$EMo \  
'j84-U{&)  
private String sSiteURL; //Site's URL ,wJ#0?  
private String sFilePath; //Saved File's Path |1GR:b24  
private String sFileName; //Saved File's Name v:*t5M >  
private int nSplitter; //Count of Splited Downloading File $vNz^!zgV  
2ZMYA=[!  
W=v4dy]B  
public SiteInfoBean() f\sxx!kt  
{//nSplitter的缺省值为5 :3k&[W*  
//default value of nSplitter is 5 o8+ZgXct  
this("","","",5); t?NB#/#%x  
} 0GR\iw$[J  
ze!S4&B  
HC0q_%j  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aa8xo5tIp  
{ gxEa?QH  
sSiteURL= sURL; s; 'XX}Y  
sFilePath = sPath; CmaV>  
sFileName = sName; ]:CU.M1  
this.nSplitter = nSpiltter; 8(R%?> 8  
> }#h  
&61;v@  
} 7Y$#* 7  
W2L:  
w%=GdA=  
public String getSSiteURL() TrxZS_  
{ j4wcxZYY~  
return sSiteURL; ,?Pn-aC +  
} #J. v[bOWQ  
h^F^|WT$  
! 8q+W`{  
public void setSSiteURL(String value) z?$F2+f&  
{ {HKd="%VG  
sSiteURL = value; G}aw{Vbg_  
} # Ny  
l4+!H\2  
NET?Ep  
public String getSFilePath() JcsJfTI  
{ (lwrk(  
return sFilePath; <rUH\z5cP  
} QUL^]6$  
0HUSN_3F  
%c%0pGn8-  
public void setSFilePath(String value) =[8EQdR  
{ BZy&;P  
sFilePath = value; VeO$n*O  
} iOpMU  
jEj#|w  
)X{x\ /N  
public String getSFileName() %u\Oj \8U  
{ *"V5j#F_  
return sFileName;  :[:5^R  
}  6e,|HV  
D>9~JHB  
tx}} Kd  
public void setSFileName(String value) y:Xs/RS  
{ L/1zG/@  
sFileName = value; l2uh"!  
} wjk-$p  
sS5 ]d8  
Rk2V[R.`S  
public int getNSplitter() |FZ)5  
{ DA)+)PhY7K  
return nSplitter; Q3MG+@)S  
} D"o}XTH  
1PWs">*(  
,]?Xf >  
public void setNSplitter(int nCount) NNZ%jJy?=,  
{ ":E^&yQ  
nSplitter = nCount; 7Iu^ l4=2  
} %VG;vW\V  
} d (Ufj|;  
Y1a[HF^-  
,bT|:T@ny  
/* M,]C(f>  
**Utility.java 3R(GO.n=]  
*/ B6)d2O9C  
package NetFox; !mNXPqnN  
VU+`yQp  
IXb]\ )  
public class Utility { } ).rD  
,at"Q$)T  
x)eYqH~i  
public Utility() K_/8MLJQ  
{ $qkV u  
4Q2=\-KFj  
}7iWmXlI  
} PI{;3X}9$,  
;J|sH>i  
//线程睡眠 *,$cW ,LN  
public static void sleep(int nSecond) 9(?9yFbj5  
{ Cz=HxU80J  
try{ SN!TE,=I  
Thread.sleep(nSecond); s*`_Ka57]~  
} >ZMB}pt`  
catch(Exception e) A4RA5N/}  
{ XWH{+c"  
e.printStackTrace (); Il(p!l<Xz#  
} 5W/!o&x~7  
} _`yd"0 Ux  
 pME17 af  
//日志 ZH8O%>!  
public static void log(String sMsg) r[xj,eIb  
{ \_?A8F  
System.err.println(sMsg); VwfeaDJw  
} ^):m^w.  
$hexJzX  
~B!O X  
public static void log(int sMsg) 9kmEg$WM  
{ 0zrgK;9  
System.err.println(sMsg); DG& ({vy  
} (XtN3FTY  
} eQh@.U*S)  
]IbX<  
oRl~x^[%[-  
/* X v[5)4N  
**TestMethod.java 6&8([J  
*/  8bQ\7jb  
package NetFox; Vfkm{*t)  
O <;Au|>*  
l,cnM r^.W  
public class TestMethod { ks92-%;:  
up+W[#+  
v+a$Xh3Y~  
public TestMethod() u{#}Lo>B #  
{ ///xx/weblogic60b2_win.exe e>yPFXSk  
try{ Y~ j.Kt  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (Fc\*Vn  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2$=U#!OtU  
SiteFileFetch fileFetch = new SiteFileFetch(bean); \Fd6Q_  
fileFetch.start(); NfG<!  
} B/"TaXVU  
catch(Exception e){e.printStackTrace ();} ,(d\!T/]'  
: utY4  
?y1']GAo  
} AY]dwKw  
}DH3_M!  
}^|g|xl!  
public static void main(String[] args) uTsxSkHb/  
{ { Ju  
new TestMethod(); Z(Styn/x  
} a?Q\nu1  
} W+HiH`Qb]  
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