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http断点续传简单实现(java)

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/* w (1a{m?ht  
**SiteFileFetch.java ],|B4\b;  
*/ AJ u.  
package NetFox; A\Gw+l<h,  
import java.io.*; \9^@,kfP  
import java.net.*; "N_?yA#(j  
tAUMSr|?  
nc)`ISI  
public class SiteFileFetch extends Thread { H_^c K  
{VG6m Hw  
R2@u[  
SiteInfoBean siteInfoBean = null; //文件信息Bean a6_`V;  
long[] nStartPos; //开始位置 ' iK0Wr  
long[] nEndPos; //结束位置 uip]K{/A!e  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 rg\w!L(  
long nFileLength; //文件长度 #4>F%_  
boolean bFirst = true; //是否第一次取文件 XLT<,B}e  
boolean bStop = false; //停止标志 W!*vO>^1W  
File tmpFile; //文件下载的临时信息 AbB>ZT>hR  
DataOutputStream output; //输出到文件的输出流 +fN0> @s  
KMZ`Wn=  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) rf@81Ds  
public SiteFileFetch(SiteInfoBean bean) throws IOException |*i-Q @ D  
{ WW=7QC i  
siteInfoBean = bean; @$]h[   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); S8l+WF4q  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); M;R>]wP"V  
if(tmpFile.exists ()) Tx_ LH"8  
{ 7Z_iQ1  
bFirst = false; )SuJK.IF  
read_nPos(); 0P42C{>'w  
} 5]E5V@C   
else ?$Pj[O^hl  
{ ~m7+^c@,  
nStartPos = new long[bean.getNSplitter()]; vNIQc "\-  
nEndPos = new long[bean.getNSplitter()]; ,U}8(D~:  
} 75y#^pD?c  
"5Mo%cUp  
z~qQ@u|  
Qw:j2g2H7  
} KMV!Hqkk  
O9Aooe4W=  
\=)h6AG  
public void run() (!s[~O6  
{ jk@]d5  
//获得文件长度 d<o  
//分割文件 ^_uzr}LE`  
//实例FileSplitterFetch =RA6p  
//启动FileSplitterFetch线程 5> UgBA  
//等待子线程返回 {8Ll\j@ "  
try{ X9R-GT  
if(bFirst)  ~$B ,K]  
{ eR CGr?e4  
nFileLength = getFileSize(); P\JpE  
if(nFileLength == -1) 0W)_5f&  
{ n !QjptQ  
System.err.println("File Length is not known!"); DWAU8>c+  
} @,]v'l!u  
else if(nFileLength == -2) [>E0(S]  
{ `*]r.u0  
System.err.println("File is not access!"); })B)-8  
} ^:BRbp37i  
else l< Y x  
{ ~$`b{  
for(int i=0;i<nStartPos.length;i++) A.[T#ZB.4  
{ =LRUasF  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !s$fqn 6  
} zv41Yv!x}  
for(int i=0;i<nEndPos.length-1;i++) o9/P/PZ\X  
{ &m`  
nEndPos = nStartPos[i+1]; =GF+hM/~  
} j[9 B,C4  
nEndPos[nEndPos.length-1] = nFileLength; 99 [ "I:  
} ;$Y?j8g  
} 7 ?Fl [FW$  
QO8/?^d  
 [7bY(  
//启动子线程 +=R:n^r^,  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?NL2|8  
for(int i=0;i<nStartPos.length;i++) ~'ovJ46tx  
{ XP'KgTF  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xe5J  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),  6?6 u  
nStartPos,nEndPos,i); z"<PveVo  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |^ qW   
fileSplitterFetch.start(); t5&$ y`  
} 1g;3MSn~  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n}l Z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HBt?cA '  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &5B+8>  
nEndPos = " + nFileLength); "783F:mPh  
// fileSplitterFetch[nPos.length-1].start(); C oaqi`v4T  
]C!u~A\jq  
 *q^'%'  
//等待子线程结束 ! M bRI  
//int count = 0; G 5)?!  
//是否结束while循环 _?{2{^v  
boolean breakWhile = false; 6c2fqAF>i  
F?UL0Q|uv  
BjA|H  
while(!bStop) !%Ak15o  
{ RKe19l_V  
write_nPos(); E(TY%wO  
Utility.sleep(500); b`^$2RM&  
breakWhile = true; +G?3j,a\  
(k[<>$hL*  
eN/Jb;W  
for(int i=0;i<nStartPos.length;i++) @-hy:th#  
{ h.67] U7m  
if(!fileSplitterFetch.bDownOver) 4EOu)#  
{ X3nwA#If1  
breakWhile = false; U<*dDE~z  
break; 2-$R@ SVy  
} 0Vg8o @  
} 2W}RXqV<  
if(breakWhile) z.QW*rW9  
break; Cnn,$R=/s  
IRpCbTIXK  
O". #B  
//count++; Z I8p(e  
//if(count>4) ~sM334sQ  
// siteStop(); zNB G;\ W  
} &B))3WFy  
=14pEe  
=~R 0U  
System.err.println("文件下载结束!"); Ar|_UV>Zf  
} Wjj'yqBO^  
catch(Exception e){e.printStackTrace ();} y_\d[  
} *QrTZ$\C  
[ P 8e=;  
a+ ]@$8+  
//获得文件长度 2^|*M@3r  
public long getFileSize() j3$KYf`T}  
{ F.JE$)B2EX  
int nFileLength = -1; P/^:IfuR  
try{ 5Eq_L  
URL url = new URL(siteInfoBean.getSSiteURL()); \wTW hr0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  HSTtDTo  
httpConnection.setRequestProperty("User-Agent","NetFox"); GLEGyT?~  
zhFGMF1  
%R}}1  
int responseCode=httpConnection.getResponseCode(); Rrsz{a  
if(responseCode>=400) v=|ahsYC  
{ rl!c\  
processErrorCode(responseCode); `DEz ` D  
return -2; //-2 represent access is error 6}[W%S]8  
} gPDc6{/C<  
yXl zImPn  
'GAjx{gM  
String sHeader; ,KZ_#9[>  
X.g1 312~  
:c c#e&BO  
for(int i=1;;i++) <x,$ODso  
{ {"O'kx  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [7$.)}Q-  
//Utility.log(in.readLine()); '#^ONnSTn  
sHeader=httpConnection.getHeaderFieldKey(i); ~]}7|VN.}  
if(sHeader!=null) ny{|{ a  
{ qRTy}FU1  
if(sHeader.equals("Content-Length")) uZi]$/ic  
{ )bqO}_B  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dk/;`sXV  
break; 7 v#sr<  
} BsR xD9r  
} I:[3x2H  
else {G_ZEo#x8,  
break; ) _"`{2  
} fAYm3+.l3  
} XD9lox  
catch(IOException e){e.printStackTrace ();} u PjJ>v  
catch(Exception e){e.printStackTrace ();} l,L#y 4#  
cu.f]'  
9FK%"s`  
Utility.log(nFileLength); $5:j" )$,  
waldLb>7D  
qY0p)`3!%  
return nFileLength; ?PLf+S  
} Hcuvu[)T"  
`}"*i_0-5'  
;ZB[g78%R%  
//保存下载信息(文件指针位置) Q R;Xj3]v  
private void write_nPos()   "Qm  
{ e5C560  
try{ `9%@{Ryo  
output = new DataOutputStream(new FileOutputStream(tmpFile)); v-EcJj%  
output.writeInt(nStartPos.length); 1%t9ic  
for(int i=0;i<nStartPos.length;i++) Y@F@k(lOo  
{ mZ'`XAS~;  
// output.writeLong(nPos); c V=h 8F  
output.writeLong(fileSplitterFetch.nStartPos); (m25ZhW  
output.writeLong(fileSplitterFetch.nEndPos); Z_Hc":4i  
} YrFB~z.V  
output.close(); *e!0ZB3J  
} ^ola5wD  
catch(IOException e){e.printStackTrace ();} P;{f+I|`  
catch(Exception e){e.printStackTrace ();} )mS Aog<  
} *ax$R6a#X  
V~%!-7?  
_|`S9Nms  
//读取保存的下载信息(文件指针位置) ,)|nxX  
private void read_nPos() V'^Hn?1^  
{ D!+d]A[r  
try{ .sgP3Ah  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ymiOtA Z  
int nCount = input.readInt(); ESft:3xyw  
nStartPos = new long[nCount]; ]:8:|*w  
nEndPos = new long[nCount]; Wyd,7]'z)Z  
for(int i=0;i<nStartPos.length;i++) cE$7CSR  
{ ??Q'| r  
nStartPos = input.readLong(); tY~EB.%  
nEndPos = input.readLong(); { owK~  
} fKb8)PDP  
input.close(); S2'./!3yv  
} Qk *`9  
catch(IOException e){e.printStackTrace ();} [}}?a   
catch(Exception e){e.printStackTrace ();} xp.~i*!`  
} 3{O^q/R  
' cR||VX  
+:+q,0~*]  
private void processErrorCode(int nErrorCode) |9Q4VY'";  
{ }vgeQh-G  
System.err.println("Error Code : " + nErrorCode); Z.ky=vCt  
} TFjb1 a,)  
IC"bg<L,*  
Ko|nF-r_  
//停止文件下载 8GgZAu'X  
public void siteStop() a6cq0g[#z  
{ 2x<,R/}  
bStop = true; ;shhg z$  
for(int i=0;i<nStartPos.length;i++) Bf1,(^3XH  
fileSplitterFetch.splitterStop(); % \IB_M  
4}E|CD/pZ  
%F_)!M;x  
} F<39eDNpz  
} -|YG**i/  
//负责部分文件的抓取 D,b'1=  
**FileSplitterFetch.java 3copJS  
*/ dZ K /v  
package NetFox; ;89 `!V O  
T)? : q  
:[YHJaK  
import java.io.*; LX2rg\a+%  
import java.net.*; [|.IXdJ!  
=bgzl=A`  
0A9llE  
public class FileSplitterFetch extends Thread { K[r<-6TS  
"H\1Z,P<m  
%/iD@2r  
String sURL; //File URL 5+Fr/C  
long nStartPos; //File Snippet Start Position H3CG'?{ _  
long nEndPos; //File Snippet End Position @)k/t>r(  
int nThreadID; //Thread's ID |mvY=t %  
boolean bDownOver = false; //Downing is over @K .{o'  
boolean bStop = false; //Stop identical EIQ`?8KSR  
FileAccessI fileAccessI = null; //File Access interface ^,O%E;g^#  
+?y ', Ir  
= Lt)15  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException blyU5 3g  
{ 0P i+ (X  
this.sURL = sURL;  i;B &~  
this.nStartPos = nStart; pDqX% $^  
this.nEndPos = nEnd; !1(*D*31  
nThreadID = id; L8R{W0Zr>!  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n<q1itjD  
} d^h`gu~3  
4~<78r5m  
c@f?0|66M  
public void run() %n?&#_G|  
{ fSc)PqLP  
while(nStartPos < nEndPos && !bStop) t@r>GHO  
{ ETZE.a  
ISa}Km>Q  
+guCTGD:  
try{ 3ScOJo  
URL url = new URL(sURL); ^I W5c>;|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r)<c ~\0 7  
httpConnection.setRequestProperty("User-Agent","NetFox"); gOb"-;Zw  
String sProperty = "bytes="+nStartPos+"-"; M]|tXo$?  
httpConnection.setRequestProperty("RANGE",sProperty); PzF>yG[  
Utility.log(sProperty); jEhPx  
CZZwBt$P  
1?I_fA}  
InputStream input = httpConnection.getInputStream(); YF8;s4  
//logResponseHead(httpConnection); R|D%1@i]  
*{y({J  
(:er~Y}  
byte[] b = new byte[1024]; lC.Q61J@  
int nRead;  N$ oQK(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BN7]u5\7  
{ Mbm'cM&}  
nStartPos += fileAccessI.write(b,0,nRead); !#&`1cYX  
//if(nThreadID == 1) xu%_Zt2/?j  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dxvizd>VU  
} 1FA:"0lO  
(}B3df  
E)>.2{]C>  
Utility.log("Thread " + nThreadID + " is over!"); >G9YYt~  
bDownOver = true; *RYok{w  
//nPos = fileAccessI.write (b,0,nRead); ^O6eFD U  
} G]v BI=  
catch(Exception e){e.printStackTrace ();} 6+ UTEw;  
} LO;7NK  
} (jmF7XfU  
>;Ag7Ex  
\^oI3K0`  
//打印回应的头信息 <#nt?Xn  
public void logResponseHead(HttpURLConnection con) s,CN<`/>x  
{ x`:c0y9uG  
for(int i=1;;i++) PQj'D <G  
{ XgI;2Be+&a  
String header=con.getHeaderFieldKey(i); o' EJ,8  
if(header!=null) *q&^tn b  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;{lb_du2:  
Utility.log(header+" : "+con.getHeaderField(header)); E]O/'-  
else  L}=DC =E  
break; :X*$U ~aQ  
} S:lie*Aux*  
} eC{St0  
8AVtUU  
?ESsma6  
public void splitterStop() 3d`u!i?/  
{ 4^Ke? ;v  
bStop = true; C;3  
} mWUkkR(/  
-{XDQ{z<%  
ZS<`.L6B3  
} nV:RL|p2jw  
"l 8YD&q  
XvSng"f.  
/* icK$W2<8mg  
**FileAccess.java =4[ U<opP  
*//文件访问(定位,写) Hk f<.U  
package NetFox; 3y tlD'  
import java.io.*; :i3 W U%  
=odKi"-6  
yGY:EvH^?  
public class FileAccessI implements Serializable{ V]Rt[l]  
|b4f3n  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Skg}/Ek  
RandomAccessFile oSavedFile; +!Q*ie+q  
long nPos; S3UJ)@ E  
u!-v1O^[  
4L bll%[9  
public FileAccessI() throws IOException XL7||9,(h  
{ '=0l{hv@  
this("",0); TKp2C5bX  
} '':MhRb  
x7xMSy  
.uinv  
public FileAccessI(String sName,long nPos) throws IOException !]3kFWs  
{ MTip4L W9  
oSavedFile = new RandomAccessFile(sName,"rw"); cT5BBR   
this.nPos = nPos; p\P)    
oSavedFile.seek(nPos); =w!2R QB  
} Wl7S<>hg4  
Q?V+ 0J  
*/HW]x|?V~  
public synchronized int write(byte[] b,int nStart,int nLen) |~o0 -: 'C  
{ I!#WXK  
int n = -1; v|MT^.  
try{ Cg(&WJw(ep  
oSavedFile.write(b,nStart,nLen); sd%m{P2  
n = nLen; | |L^yI~_d  
} &5[B\yv  
catch(IOException e) nAC>']K4$  
{ ]N2! 'c  
e.printStackTrace (); h1H$3TpP  
} QHxof7  
H$V`,=H  
dT0>\9ZNr  
return n; j#Qnu0D  
} F9"Xu-g  
Z~w2m6;s  
O!t=,F1j  
} Ih N^*P:Fo  
LzxO=+=9!q  
8|(],NyEJ  
/* /'/i?9:  
**SiteInfoBean.java 4jc?9(y%  
*/ vjzG H*  
package NetFox; D |=L)\  
$<9u:.9xf  
AhkDLm+  
public class SiteInfoBean { yDJy'Z_F{  
Gr>CdB>~+  
)FSEHQ  
private String sSiteURL; //Site's URL ol K+|nR  
private String sFilePath; //Saved File's Path +|x{?%.O  
private String sFileName; //Saved File's Name G`;\"9t5h  
private int nSplitter; //Count of Splited Downloading File m[z $y  
(I`lv=R"j  
`v-O 4Pk  
public SiteInfoBean() :`4F0  
{//nSplitter的缺省值为5 a`8]TD  
//default value of nSplitter is 5 &Yo|Pj  
this("","","",5); FJ^\K+;  
} yh/JHo;  
UM`{V5NG#  
*$5p,m6G  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /+*N.D'`t,  
{ h$}PQ   
sSiteURL= sURL; 1]9w9! j  
sFilePath = sPath; QJ(5o7Tfn  
sFileName = sName; )dFPfu&HL  
this.nSplitter = nSpiltter; 3yw$<lm  
6#AEVRJKU@  
'oK o F  
} p/88mMr  
8rx|7  
5F!Qn\{u{  
public String getSSiteURL() `*elzW  
{ ak-agH  
return sSiteURL; [?hvx}  
} [Y~~C J  
MN8>I=p  
&CcW(-  
public void setSSiteURL(String value) ]Y-Y.&b7t  
{ |N^"?bSt  
sSiteURL = value; _n/73Oh  
} C\joDAD  
g ?xD*3 <  
4U_+NC>b  
public String getSFilePath() :<mJRsDf  
{ F+GX{e7E\  
return sFilePath; /G|v.#2/g  
} yXoNfsv  
4lWqQVx  
VdGVEDwz  
public void setSFilePath(String value) K a& 2>F  
{ PO8Z2"WI  
sFilePath = value; #0vda'q=j  
} ; o Y|~  
|d&C<O;f  
 ,vO\n^  
public String getSFileName() S0Io$\ha  
{ kz1#"8Zd!  
return sFileName; /a<UKh:A[  
} Kc95yt  
7y&6q`y E  
nu7 R  
public void setSFileName(String value) nGe4IY\-w  
{ vy}_aD{B  
sFileName = value; 4I$Y"|_e  
} ;[UI ]?A%  
e[?,'Mp9  
:V5 Co!/+  
public int getNSplitter() BWQ`8  
{ SMIDW}U2S  
return nSplitter; <F(S_w62  
} [qW%H,_  
4sntSlz)~k  
2$kB^g!:o  
public void setNSplitter(int nCount) bhGRD{=  
{ _/z_ X  
nSplitter = nCount; tkR~(h  
} jL8A_'3B  
} Z5n-3h!+ED  
w|]Tt="   
Z$g'h1,zW  
/* vanV|O  
**Utility.java [5p3:D  
*/ l"(PP3  
package NetFox; Gp \-AwE  
MZ&.{SY7  
MH#"dGGu  
public class Utility { 1;1;-4k7I  
A$N%deb  
6IV):S~  
public Utility() &Z[+V)6,,  
{ Pj]^ p{>  
(3mL!1\  
p<(a);<L  
} @'}2xw[eU  
]7cciob  
//线程睡眠 @IsUY(Gu  
public static void sleep(int nSecond) ?4U4o<   
{ S*=^I2;  
try{ LdH1sHy*d`  
Thread.sleep(nSecond); S9P({iZK  
} oJ %Nt&q  
catch(Exception e) m3Wc};yE*Q  
{ W{.:Cf9  
e.printStackTrace (); =DfI^$Lr:  
} zN!yOlp5  
} rP'%f 6  
HZ%V>88  
//日志 wkGr}  
public static void log(String sMsg) Iy49o!  
{ %6 Av1cv  
System.err.println(sMsg); fMFkA(Of^  
} &"JC8  
^7/v[J<<  
H390<`  
public static void log(int sMsg) L=qhb;  
{ AV2Jl"1)z  
System.err.println(sMsg); 5I2 h(Td  
} '%t$m f!nV  
} %;ED} X  
HBR/" m  
gEsD7]o(=  
/* 8)eRm{  
**TestMethod.java U ->vk{v  
*/ APF`b  
package NetFox; 8v2Wi.4T  
P8ej9ULX,  
@}H'2V  
public class TestMethod { MYvz%7  
t2{(ETV  
-e(<Jd_=  
public TestMethod() -s2)!Iko&  
{ ///xx/weblogic60b2_win.exe jd ;)8^7K  
try{ Qc-W2%  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g2TK(S|#  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r3U7`P   
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jj [3rt?8  
fileFetch.start(); Mn/  
} gizY4~ j  
catch(Exception e){e.printStackTrace ();} 1}|y^oB\-  
yN{**?b  
jZqa+nG51  
} [dP<A ?s  
]~dB| WB  
,&4 [`d  
public static void main(String[] args) 8 A]8yX =  
{ 0'r}]Mws  
new TestMethod(); >S`=~4  
} #e-7LmO~  
} paD[4L?4Hk  
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