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http断点续传简单实现(java)

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/* S+G)&<a^  
**SiteFileFetch.java 4QNR_w  
*/ .B13)$C  
package NetFox; pxx(BE  
import java.io.*; r\d:fot  
import java.net.*; clw91yrQn  
'qJ-eQ7e  
^Q>*f/.KN  
public class SiteFileFetch extends Thread { JWL J<z  
-/%jeDKp  
Ol[gck|~  
SiteInfoBean siteInfoBean = null; //文件信息Bean o }A #-   
long[] nStartPos; //开始位置 ea0tx3'  
long[] nEndPos; //结束位置 HqBPY[;s  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 >G2-kL_  
long nFileLength; //文件长度 PuaosMn(9  
boolean bFirst = true; //是否第一次取文件 D 8Rmxq!  
boolean bStop = false; //停止标志 @U{M"1zZe  
File tmpFile; //文件下载的临时信息 8 36m5/kH[  
DataOutputStream output; //输出到文件的输出流 JZzf,G:  
hH}/v0_jb  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) e9_+$Oo  
public SiteFileFetch(SiteInfoBean bean) throws IOException &|'6-wD.  
{ a7\L-T+  
siteInfoBean = bean; XB-|gPk  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); kVnyX@  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); b]BA,D 4  
if(tmpFile.exists ()) 7V (7JV<>  
{ =bWq 3aP)P  
bFirst = false; _kN%6~+U  
read_nPos(); )c/y07er  
} )`mF.87b&h  
else o$VH,2 QF  
{ >;v0zE  
nStartPos = new long[bean.getNSplitter()]; F |81i$R  
nEndPos = new long[bean.getNSplitter()]; +c`C9RXk  
} ~4MjJKzA  
RCYbRR4y  
"n }fEVJ,  
P &0cF{  
} lhl 0  
Ko)T>8:  
.oj"ru  
public void run() 43=-pyp  
{ sDm},=X}  
//获得文件长度 y%bqeo L~  
//分割文件 #0^3Wm`X;  
//实例FileSplitterFetch D{c>i`\G  
//启动FileSplitterFetch线程 8'"/gC{  
//等待子线程返回 %@93^q[\2  
try{ NoZ4['NI\  
if(bFirst)  _np>({  
{ Uv`v|S:+2  
nFileLength = getFileSize(); h_G|.7!  
if(nFileLength == -1) 9~'Ip7X,!  
{ */dh_P<Yj  
System.err.println("File Length is not known!"); "Vp: z V<S  
} -!G#")<  
else if(nFileLength == -2) 9c}]:3#XO  
{ `AHNk7 t=  
System.err.println("File is not access!"); 5z w23!  
} )|R0_9CLV  
else JS?l?~  
{ [pgkY!R?)  
for(int i=0;i<nStartPos.length;i++) OXX(OCG>  
{ w^E]N  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); GdeR#%z  
} R 4QwWSBJ  
for(int i=0;i<nEndPos.length-1;i++) e=)* O  
{ ZX6=D>)u  
nEndPos = nStartPos[i+1]; ; :\,x  
} lEb R)B,  
nEndPos[nEndPos.length-1] = nFileLength; k,iV$,[TF  
}  Ox*T:5  
} -_*XhD  
B m@oB2x)  
?Wz(f{Hm  
//启动子线程 k=~pA iRDN  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >wk=`&+V@  
for(int i=0;i<nStartPos.length;i++) RyQ\5^z  
{ gc:p@<  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h8= MVh(I  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9 roth  
nStartPos,nEndPos,i); YSz$` 7i  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?CW^*So  
fileSplitterFetch.start(); P}WhE  
} _E<O+leWf  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X1V}%@3:  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MN M>  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]#-/i2-K  
nEndPos = " + nFileLength); i 2} =/  
// fileSplitterFetch[nPos.length-1].start(); 5A]LNA4i  
f+aS2k(e>  
Ta\8 >\6  
//等待子线程结束 9Glfi@.  
//int count = 0; Ysc|kxLb  
//是否结束while循环 '"fU2M<.  
boolean breakWhile = false; nP{sCH 1  
Z=Y_;dS9  
0CVsDVA  
while(!bStop) \%?8jQ'tX  
{ 7- 3N  
write_nPos(); ocA'goI-  
Utility.sleep(500); z'} =A  
breakWhile = true; c;8"vJ  
a2=uM}Hsp  
K-Dk2(x  
for(int i=0;i<nStartPos.length;i++) Or#+E2%1E  
{ # /,2MQ  
if(!fileSplitterFetch.bDownOver) pT;-1c%:  
{ c>WpOZ,  
breakWhile = false; g*r{!:,t  
break; VRQbf  
} [cL U*:  
} =.f +}y  
if(breakWhile) :*&9TNU E@  
break; 73s3-DS,  
bR8 HGH28  
z2nUul(2  
//count++; PxVI {:Uz  
//if(count>4) 6v2RS  
// siteStop(); 3{I=#>;  
} #9hXZr/8  
x [{q&N!"`  
QOh w  
System.err.println("文件下载结束!"); mLk6!&zN  
} e<O;pM:  
catch(Exception e){e.printStackTrace ();} Fb{`a[&  
} >upXt?  
kSDa\l!W]  
hKzBq*cV  
//获得文件长度 *CPB5s  
public long getFileSize() sg6w7fp>  
{ oA3W {  
int nFileLength = -1; E_![`9i  
try{ %L\{kUam  
URL url = new URL(siteInfoBean.getSSiteURL()); K,C $J I  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M\?uDC9  
httpConnection.setRequestProperty("User-Agent","NetFox"); pW3)Y5/D  
@a.6?.<L  
1l|A[ G  
int responseCode=httpConnection.getResponseCode(); ; LF)u2x=  
if(responseCode>=400) F<oc Y0=9p  
{ C>`.J_N  
processErrorCode(responseCode); 9*TS90>a  
return -2; //-2 represent access is error ),y!<\oQ  
} rm)SfT<  
S `m- 5  
JX\T {\m#  
String sHeader; ;*g*DIR  
H6PXx  
kO,VayjT  
for(int i=1;;i++) wUIsi<Oj  
{ /VmCN]2AZ  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9?l?G GmQ  
//Utility.log(in.readLine()); (4{ C7  
sHeader=httpConnection.getHeaderFieldKey(i); srChY&h?<  
if(sHeader!=null) gSv[4,hXd  
{ L%o65  
if(sHeader.equals("Content-Length")) 8W1K3[Jj<  
{ .y;\puNq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bDh:!M  
break; ]lB3qEn<  
} 8%2rgA  
} WDoKbTv  
else ><#2O  
break; mS)|6=Y  
} vzohq1r5  
} &` 00/p  
catch(IOException e){e.printStackTrace ();} &8X .!r`f  
catch(Exception e){e.printStackTrace ();} n$OE~YwP{  
hk5E=t~&  
l#5~ t|\  
Utility.log(nFileLength); B::4Qme  
LpiHoavv  
7$1fy0f[l  
return nFileLength; S`W'G&bCj  
} a$xeiy9  
iKF$J3a\2f  
dY4k9p8  
//保存下载信息(文件指针位置) iBtjd`V*  
private void write_nPos() +C'TW^  
{ >TlW]st  
try{ j2 o1"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); !0!U01SWa  
output.writeInt(nStartPos.length); /.| A  
for(int i=0;i<nStartPos.length;i++) V &mH#k  
{ cz7 CrK~5  
// output.writeLong(nPos); ySixYt  
output.writeLong(fileSplitterFetch.nStartPos); y ;{^Ln4{  
output.writeLong(fileSplitterFetch.nEndPos); D8@n kSP  
} x:A-p..e  
output.close(); ?2?S[\@`0U  
} T]Tdx.B  
catch(IOException e){e.printStackTrace ();} fd5ZaE#f  
catch(Exception e){e.printStackTrace ();} OD?y  
} l}Q"Nb)  
#90[PASx  
jIx8k8  
//读取保存的下载信息(文件指针位置) AK@`'$  
private void read_nPos() m{b ZRkt  
{ n2xLgK=  
try{ Ss#@=:"P  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 68koQgI[^  
int nCount = input.readInt(); ( K6~Tj  
nStartPos = new long[nCount]; `x{.z=xC  
nEndPos = new long[nCount]; wDT>">&d  
for(int i=0;i<nStartPos.length;i++) N"Qg\PS_  
{ 3wN?|N  
nStartPos = input.readLong(); Yo~LckFF  
nEndPos = input.readLong(); "wnpiB}  
} ;t;Y.*&=S  
input.close(); PJxak3  
} VxkCK02k  
catch(IOException e){e.printStackTrace ();} ZR;8r Z](  
catch(Exception e){e.printStackTrace ();} z.2r@Psk  
} (|0.m8D~D  
E ;BPN  
sJ))<,e5I  
private void processErrorCode(int nErrorCode) _KB{J7bs<a  
{ V>b2b5QAH,  
System.err.println("Error Code : " + nErrorCode); }J ei$0x  
} '%zN  
W>5vRwx00  
,hpH!J'5f/  
//停止文件下载 ~ON1Zw[+  
public void siteStop() *#&k+{a^2  
{ ^CZCZ,v  
bStop = true; d5@X#3Hd  
for(int i=0;i<nStartPos.length;i++) ADv^eJJ|  
fileSplitterFetch.splitterStop(); &a%WM   
a|DsHZ^6^  
Q^z=w![z  
} prNhn:j  
} IVI~1~  
//负责部分文件的抓取 ./'~];&  
**FileSplitterFetch.java FAQr~G}  
*/ mu6039qy  
package NetFox; s<[A0=LH  
,O:EX0  
h>}ax\h  
import java.io.*; H~A"C'P3#  
import java.net.*; _j:UGMTi(U  
;{<aA 5  
\~JNQ&_o  
public class FileSplitterFetch extends Thread { +h0PR?  
$& cz$jyY  
:J^qjAV  
String sURL; //File URL :ozV3`%$(  
long nStartPos; //File Snippet Start Position vU=9ydAj?  
long nEndPos; //File Snippet End Position "$XYIuT  
int nThreadID; //Thread's ID yXJ]U \ %  
boolean bDownOver = false; //Downing is over J|V K P7  
boolean bStop = false; //Stop identical 9T(L"9r-e  
FileAccessI fileAccessI = null; //File Access interface ;B&^yj&;  
e^j<jV`1  
c_ La^HS  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bGbqfO`  
{ 2t+D8 d|c<  
this.sURL = sURL; Fi mN?s  
this.nStartPos = nStart; nz4<pvC,*  
this.nEndPos = nEnd; *IC^IC:  
nThreadID = id; >[ eW">:>K  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ')B =|T)  
} >T<6fpXuk2  
>^a$  
^>C 11v  
public void run() yL0f1nS  
{ 7ftR 4  
while(nStartPos < nEndPos && !bStop) ,4[dLWU  
{ \gLxC  
k`Nyi )AGe  
D^Te%qnW  
try{ w/ TKRCO3  
URL url = new URL(sURL); l , ..5   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {Fbg]'FQ  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]eE 1n2  
String sProperty = "bytes="+nStartPos+"-"; .*BA 1sjE  
httpConnection.setRequestProperty("RANGE",sProperty); #~L!pKM  
Utility.log(sProperty); 5sCFzo<=vh  
sf(i E(o  
o]Gguw5W{  
InputStream input = httpConnection.getInputStream(); z~,mRgc$B  
//logResponseHead(httpConnection); |6aJwe+*  
3UdU"d[75  
v:E;^$6Vn  
byte[] b = new byte[1024]; iOXZ ]Xj5  
int nRead; i[\w%(83Fi  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) / s,tY74'5  
{ e@E17l-  
nStartPos += fileAccessI.write(b,0,nRead); dL-i)F  
//if(nThreadID == 1) Vtr3G.P^  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ly;I,)w  
} tJNIr5o  
zh\$t]d<I  
4o<*PPA1  
Utility.log("Thread " + nThreadID + " is over!"); w5`#q&?  
bDownOver = true; CEuWw:)  
//nPos = fileAccessI.write (b,0,nRead); (89Ji'dc  
} C5|db{=\.*  
catch(Exception e){e.printStackTrace ();} <47k@Ym   
} 7h%4]  
} *m9{V8Yi2  
LN4qYp6)G  
4S|=/f  
//打印回应的头信息 k;k}qq`d  
public void logResponseHead(HttpURLConnection con) iK#/w1`  
{ l4rMk^>>  
for(int i=1;;i++) ldGojnS  
{ W^es;5  
String header=con.getHeaderFieldKey(i); VPt9QL(  
if(header!=null) `5q ;ssu  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yEq#Dr  
Utility.log(header+" : "+con.getHeaderField(header)); *^] ~RhjB  
else Tzzq#z&F  
break; {CtR+4KD  
} d|XmasGN  
} "xe=N  
=7%o E[  
V|'1tB=;*1  
public void splitterStop() !nd*W"_gQ/  
{ @Y}uZ'jt'  
bStop = true; 7{e=="#*  
} @5.e@]>ZM  
MPIlSMe  
X8i(~ B  
} ySe$4deJ  
]N^*tO  
YuQ~AE'i  
/* lwT9~Hyp  
**FileAccess.java D'b#,a;V  
*//文件访问(定位,写) %T!J$a)qf  
package NetFox; ?P/AC$:|I  
import java.io.*; 6BocGo({  
tu0aD%C  
bUZ_UW  
public class FileAccessI implements Serializable{ `pL^}_>|GM  
Zp&@h-%YoD  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !lTda<;]  
RandomAccessFile oSavedFile; /*$hx@ih  
long nPos; fuUm}N7  
@*>Sw>oet  
C$d>_ r  
public FileAccessI() throws IOException t{dSX?<nt  
{ AQss4[\Dx  
this("",0); } fZ`IOf  
} h5"Ov,K3[  
\, &9  
@?kM'*mrZM  
public FileAccessI(String sName,long nPos) throws IOException $g10vF3  
{ D\1k.tI  
oSavedFile = new RandomAccessFile(sName,"rw"); >\2:\wI  
this.nPos = nPos; kL>d"w  
oSavedFile.seek(nPos); @F~LW6K  
} ^e Gue  
]]0,|My7  
 En6H%^d2  
public synchronized int write(byte[] b,int nStart,int nLen) p`F9Amb  
{ *|% ^0#$c  
int n = -1; B=Ym x2A9]  
try{ . ]@=es  
oSavedFile.write(b,nStart,nLen); 2HD]?:Fk7  
n = nLen; k |YWOy@D~  
} yClx` S(  
catch(IOException e) +Qxu$#  
{ 71fk.16  
e.printStackTrace (); m ee$"Y  
} l|/LQ/  
- nbMTY}  
S'LZk9E  
return n; )IL #>2n?  
} .8WXC   
({^9<Us  
e>}}:Ud  
} \ HZ9S=  
"TcW4U9  
g(C|!}ex/  
/* 4|?{VQ  
**SiteInfoBean.java Oakb'  
*/ 7.Kc:7  
package NetFox; #A7jyg":  
C? 4JXW  
d[D&J  
public class SiteInfoBean { S6d`ioi-  
kc `V4b%  
uC3:7  
private String sSiteURL; //Site's URL SOZPZUUEJ  
private String sFilePath; //Saved File's Path %dST6$Z  
private String sFileName; //Saved File's Name & fC!(Oy  
private int nSplitter; //Count of Splited Downloading File ao" %WX  
Sh6JF574T  
+pm[f["C.  
public SiteInfoBean() :}:3i9e*2  
{//nSplitter的缺省值为5 mmXm\]r>4  
//default value of nSplitter is 5 V/d/L3p  
this("","","",5); }x0- V8  
} ^Xb7[ +I6  
;Q;[*B=kE  
l_tw<`Ep  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %V`F!D<D  
{ #H?t!DU  
sSiteURL= sURL; !$;a[Te  
sFilePath = sPath; YgUH'P-  
sFileName = sName; WE6a'  
this.nSplitter = nSpiltter; B/JO~;{  
-t2T(ha  
7dG 79H  
} *OJ/V O  
-|k)tvAm  
LQ11ba  
public String getSSiteURL() J5p"7bc  
{ [#Lc]$  
return sSiteURL; #11NPo9  
} Uxfl_@lJ  
57a2^  
D4Al3fe  
public void setSSiteURL(String value) `;|5  
{ ^9OUzTF  
sSiteURL = value; [D-Q'"'A  
} 9^"b*&>P  
g"s$}5{8:  
,#FLM`  
public String getSFilePath() 1"7Sy3  
{ xkNyvqcw  
return sFilePath; Rlnbdb;!k  
} 1OLqL  
5!YA o\S  
%J:SO_6  
public void setSFilePath(String value) bzDIhnw  
{ 8P7"&VYc8  
sFilePath = value; 2kAx>R  
} S{4z?Ri, '  
?\KM5^eX  
Hs?e0Z=N  
public String getSFileName() E!BPE>  
{ 7]xm2CHx5  
return sFileName; ]M/9#mD9~  
} t^]$!H  
fkSO( C)  
7cAXd#sI  
public void setSFileName(String value) E:zF/$tG  
{ -K,-h[ o  
sFileName = value; ]<(]u#g_d  
} Y2B &go  
_lzyMEdr  
\^(0B8|w  
public int getNSplitter() Uoya3#4 G  
{ [ EFMu;q  
return nSplitter; Djk C  
} Uz cx6sw  
2%*MW"Q  
] Z8Vj7~  
public void setNSplitter(int nCount) b2 _Yu^  
{ t?o ,RN:  
nSplitter = nCount; b|Q)[y]  
} QB.J,o*XD4  
} CQel3Jtt.  
du$|lxC  
W$U0[^1  
/* O#wpbrJ  
**Utility.java ,B4VT 96*  
*/ 6sIL.S~c)  
package NetFox; PB%-9C0  
L %ip>  
M8H5K  
public class Utility { +^*iZ6{+7  
PJxH7|GSi  
'(? uPr  
public Utility() }:0uo5 B7  
{ D7Y)?Z5A;  
?USQlnr:R/  
G} eUL|S  
} 8WE{5#oi  
0 a]/%y3V  
//线程睡眠 ~~/xR s  
public static void sleep(int nSecond) ^c~)/F/cF  
{ LjL[V'JL  
try{ f.24:Dw,  
Thread.sleep(nSecond); ~GE$myUT\p  
} =@TQ>Qw%b  
catch(Exception e) o=FE5"t  
{ eC5$#,HiC  
e.printStackTrace (); ^pM+A6 XY  
} +<,gB $j  
} NmMIQ@K  
;8!Z5H  
//日志 dU\%Cq-G)  
public static void log(String sMsg) *[=bR>  
{ "V{yi!D{<  
System.err.println(sMsg); G:x*BH+  
} yj4+5`|f  
# :T-hRu  
pJN${  
public static void log(int sMsg) 0$7.g!h?  
{ cA6lge<{~  
System.err.println(sMsg); XeBP`\>Ve  
} .>z][2oz  
} eIl]oC7*  
xBu1Ak8w  
R/"x}B1d  
/* qfcYE=  
**TestMethod.java P0 `Mdk371  
*/ Y(.OF Q  
package NetFox; 6<K6Y5<6  
4v[~r1!V  
g$. \  
public class TestMethod { @( n^T  
Ltjbxw"Qd  
=] 3tUD  
public TestMethod() bc , p }  
{ ///xx/weblogic60b2_win.exe D&HV6#  
try{ i#%aTRKHd6  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G,;,D9jO7  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EyY.KxCB  
SiteFileFetch fileFetch = new SiteFileFetch(bean); wP,JjPUt  
fileFetch.start(); fDx9iHGv  
} Mi~(aah  
catch(Exception e){e.printStackTrace ();} eT2*W$  
t>8XTqqi  
Scv#zuv_  
} iAa;6mH  
"`6n6r42  
(H+'X}1  
public static void main(String[] args) Zo>]rKeV  
{ A.UUW  
new TestMethod(); {BHI1Uw  
} pRSOYTebP  
} Gycm,Cy  
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