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http断点续传简单实现(java)

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/* })5I/   
**SiteFileFetch.java Aiqn6BX{  
*/ "Rr650w[  
package NetFox; i-`J+8|d  
import java.io.*; > ZKHjw  
import java.net.*; p!H'JNG  
K&TO8   
+y9WJ   
public class SiteFileFetch extends Thread { Ag0)> PD^  
)o_Pnq9_  
Zo T8  
SiteInfoBean siteInfoBean = null; //文件信息Bean s=83a{#K  
long[] nStartPos; //开始位置 'XW9+jj)/  
long[] nEndPos; //结束位置 e>!=)6[*  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 p [7?0 (  
long nFileLength; //文件长度 =~ [RG  
boolean bFirst = true; //是否第一次取文件 n>?eTlO3  
boolean bStop = false; //停止标志 j5bp)U  
File tmpFile; //文件下载的临时信息 "|<U`3y6  
DataOutputStream output; //输出到文件的输出流 bTW# f$q:4  
RKO}  W#?  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) _REAzxe S  
public SiteFileFetch(SiteInfoBean bean) throws IOException q?bKh*48  
{ tIL ]JB  
siteInfoBean = bean; th`pf   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); }BJR/r  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); D;+sStZK3  
if(tmpFile.exists ()) +$ 0wBU  
{ 4LkW`Sbm  
bFirst = false; zL/r V<  
read_nPos(); (Kb_/  
} ECr}7R%  
else xpB* > zb  
{ Wr;9Mz&{  
nStartPos = new long[bean.getNSplitter()]; -5d^n\CDK  
nEndPos = new long[bean.getNSplitter()]; }^zsN`  
} tu5T^"B qO  
0^ >b=a  
Ula h!s  
*8I &|)x  
} 8Ao pI3  
W|AK"vf  
Qk] ^]I  
public void run() agp7zw=N  
{ EdC/]  
//获得文件长度 tM3Q;8gB!  
//分割文件 TWSx9ii!M:  
//实例FileSplitterFetch JbLHW26pl  
//启动FileSplitterFetch线程 i.0.oy>  
//等待子线程返回 ['Y"6[1  
try{ -DL"Yw}  
if(bFirst) dd:vQOF;  
{ ZXC_kmBN/  
nFileLength = getFileSize(); }}gtz-w  
if(nFileLength == -1) 4{CeV7  
{ ^~JF7u  
System.err.println("File Length is not known!"); S$NJmXhx5  
} {YF(6wVl  
else if(nFileLength == -2) J *;= f8  
{ 57[tUO  
System.err.println("File is not access!"); s%i \z }/  
} 7&3  
else FG)(,?q  
{ e)*-<AGwC  
for(int i=0;i<nStartPos.length;i++) Y4 {/P1F  
{ FqXE6^  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); W=\45BJ  
} T$*#q('1"}  
for(int i=0;i<nEndPos.length-1;i++) 0t2n7Y?N  
{ ^50\c$  
nEndPos = nStartPos[i+1]; AS/z1M_U  
} yyM`J7]J  
nEndPos[nEndPos.length-1] = nFileLength; DLD5>  
} BI+x6S>d  
} P`AW8Y6o  
=2e{T J/  
~' w]%rh!  
//启动子线程 3wN{k\n s  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q)2i{\GPVn  
for(int i=0;i<nStartPos.length;i++) =buarxk  
{ #MUY!  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #T++5G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K8RV=3MBLD  
nStartPos,nEndPos,i); l- $5CO  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U<I]_]  
fileSplitterFetch.start(); t 09-y  
} ?.^n,[2  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l4*vM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _0"s6D$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bi[g4,`Z;  
nEndPos = " + nFileLength);  xq&r|el  
// fileSplitterFetch[nPos.length-1].start(); 1 RVs!;  
d'@i8N["{  
W<>R;~)  
//等待子线程结束 W0XfU`  
//int count = 0; W5Vh+'3  
//是否结束while循环 mjKu\7F  
boolean breakWhile = false; QB ; jZpF  
G124! ^  
KW(^-:wmr  
while(!bStop) oaG;i51!  
{ <FfmDR  
write_nPos(); 0( q:K6zI}  
Utility.sleep(500); )3.=)?XW  
breakWhile = true; |cgc^S/~H  
{$Z S 2 7  
oc;4;A-;`c  
for(int i=0;i<nStartPos.length;i++) DO6 pv  
{ xM=?ES  
if(!fileSplitterFetch.bDownOver) Jk;dtLL}4  
{ QXEz  
breakWhile = false; ~rlPS#]o  
break; !GnwE  
} 1>L8EImx]V  
} Dg*'n  
if(breakWhile) kK=f@l  
break; mcTC'. 9  
E8L\3V4  
||Vx:(d7D&  
//count++; Qt>Bvu Q  
//if(count>4) x27$h)R0v  
// siteStop(); ;$3e pP  
} T_[  
`6<Qb=  
<Vl`EfA(  
System.err.println("文件下载结束!"); <l5s[  
} T%4yPmY  
catch(Exception e){e.printStackTrace ();} >4bWXb'S}C  
} o:`^1  
`=%G&_3_<  
8ib e#jlg  
//获得文件长度 |? rO  
public long getFileSize() g%okYH?  
{ Pq1j  
int nFileLength = -1; Kx02 2rgDU  
try{ /0b7"Kr  
URL url = new URL(siteInfoBean.getSSiteURL()); j\iNag(   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ySHpN>U  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^O<@I  
Y>x3`f]  
a]!u go}  
int responseCode=httpConnection.getResponseCode(); eOahr:Db  
if(responseCode>=400) 1BSn#Dnj  
{ Vi#[k n'  
processErrorCode(responseCode); wb ^>/  
return -2; //-2 represent access is error 6Ev+!!znu  
} 5xQ5)B4k  
WO$8j2!~#  
F`>qg2wO  
String sHeader; ?}HZJ@:lB  
G "ixw  
0-p %.}GE  
for(int i=1;;i++) 5t|$Yt[  
{ Q)\[wYMt  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h{ZK;(u$  
//Utility.log(in.readLine()); r,q.RWuII  
sHeader=httpConnection.getHeaderFieldKey(i); Y$_^f*sFn  
if(sHeader!=null) ,(f({l[J}  
{ 6=96^o*  
if(sHeader.equals("Content-Length")) !-t"}^)  
{ f|Nkk*9$  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >7z(?nQYT^  
break; n[\L6}  
} nfh<3v|kvR  
} !QC ErE;r  
else h6?o)Q>N  
break; pZ]&M@Ijp  
} <) -]'@*c  
} 5=  V29  
catch(IOException e){e.printStackTrace ();} SNf~%B?`L  
catch(Exception e){e.printStackTrace ();} &yI>A1  
Oj8D+sC{  
j Q8 T  
Utility.log(nFileLength); 9%2h e)Yqc  
92~$Qa\S!  
ZCA= n  
return nFileLength; @2`nBtk  
} ng9 _c  
2InM(p7j~K  
u+c2 m  
//保存下载信息(文件指针位置) .g94|P  
private void write_nPos() _#we1m  
{ -s\R2_(  
try{ [E/. r{S  
output = new DataOutputStream(new FileOutputStream(tmpFile)); eN`G2eE  
output.writeInt(nStartPos.length); aSI%!Vg.  
for(int i=0;i<nStartPos.length;i++) i=&]%T6Qk  
{ )1 QOA  
// output.writeLong(nPos); FGeKhA 8jT  
output.writeLong(fileSplitterFetch.nStartPos); aGAr24]y  
output.writeLong(fileSplitterFetch.nEndPos); fcy4?SQ.<i  
} /N,\st  
output.close(); [fY7|  
} 7jGfQ  
catch(IOException e){e.printStackTrace ();} 0}po74x*r  
catch(Exception e){e.printStackTrace ();} CZ>Ujw=&k  
} qRz /$|.  
nRT ]oAi  
])q,mH  
//读取保存的下载信息(文件指针位置) uX%$3k  
private void read_nPos() w-C%,1F,/  
{ TaF;P GjVw  
try{  QB !%  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <U8w#dc  
int nCount = input.readInt(); 2*] [M,L0c  
nStartPos = new long[nCount]; q s:TR  
nEndPos = new long[nCount]; NC iB n>=:  
for(int i=0;i<nStartPos.length;i++)  SiJ{  
{ 6PC?*^v  
nStartPos = input.readLong(); wOLV?Vk  
nEndPos = input.readLong(); "U$](k.<VA  
} x:h)\%Dg<  
input.close(); n/e,jw  
} $GHi9aj_P  
catch(IOException e){e.printStackTrace ();} M.bkFuh  
catch(Exception e){e.printStackTrace ();} ?}= $zN  
} jv6>7@<G  
1=e(g#Ajn\  
lXEn m-_  
private void processErrorCode(int nErrorCode) ;P$ _:-C  
{ qn'TIE.  
System.err.println("Error Code : " + nErrorCode);  Sr_hD5!  
} F{_,IQ]U  
OX?E3 <8`  
L[<CEk  
//停止文件下载 ='@ k>Ka+  
public void siteStop() rq1zvuUx  
{ Z?WVSJUVf  
bStop = true; s(e1kk}"  
for(int i=0;i<nStartPos.length;i++) Fc=6 *.hy  
fileSplitterFetch.splitterStop(); 7]~|dc(  
<9T,J"y  
{,?Gj@$  
} (y1S*_D  
} @ZrNV*&<  
//负责部分文件的抓取 Hs{x Z:  
**FileSplitterFetch.java tu/4  
*/ FlY"OU*  
package NetFox; 2fNNdxdbT  
,?`kYPZ  
ly6 dl  
import java.io.*; :_`Yrx5  
import java.net.*; n xR\tBv  
=W>a~e]/  
<fA}_BH%]  
public class FileSplitterFetch extends Thread { ltMcEv-d0  
0QxBC7` qp  
t:xTmK&vt  
String sURL; //File URL 8 qZbsZi4  
long nStartPos; //File Snippet Start Position =k;X}/  
long nEndPos; //File Snippet End Position OMd:#cWsQ  
int nThreadID; //Thread's ID MBnxF^c&P  
boolean bDownOver = false; //Downing is over K<%8.mZ7  
boolean bStop = false; //Stop identical )-Z*/uF^  
FileAccessI fileAccessI = null; //File Access interface a^ys7UV  
l.Z+.<@  
cr?ZXu_  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1^ go)(Mx  
{ }lCQ+s!  
this.sURL = sURL; ]24]id  
this.nStartPos = nStart; B\% Gp}  
this.nEndPos = nEnd; G*~CB\K_  
nThreadID = id; Xq"Es  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dz/MIx  
} 5PP^w~n  
9[DlJ@T}  
ePxAZg$ `>  
public void run() Z&=Oe^  
{ }mI0D >n  
while(nStartPos < nEndPos && !bStop) ; 7QG]JX  
{ rFUd  
:LC3>x`:  
|34w<0Pc,  
try{ {xTh!ih2 -  
URL url = new URL(sURL); ~=<uYv?0s  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cv4nl7A'  
httpConnection.setRequestProperty("User-Agent","NetFox"); $iA:3DM07  
String sProperty = "bytes="+nStartPos+"-"; /CbiYm  
httpConnection.setRequestProperty("RANGE",sProperty); ,]y_[]636  
Utility.log(sProperty); J aJ/ |N  
e AaS }g 0  
+}:2DXy@  
InputStream input = httpConnection.getInputStream(); 3df5 e0  
//logResponseHead(httpConnection); 6E(..fo:"  
_c-(T&u<  
0%,?z`UY  
byte[] b = new byte[1024]; CkNh3'<wg  
int nRead; +Fh,!`  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3II*NANeg  
{ sE!g!ht  
nStartPos += fileAccessI.write(b,0,nRead); u yE#EnsH  
//if(nThreadID == 1) q-,`\ TS  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D=Yr/qc?  
} rV?@Kgxi  
+8"P*z,  
bQPO'S4  
Utility.log("Thread " + nThreadID + " is over!"); (m=1yj9  
bDownOver = true;  -rT#Wi  
//nPos = fileAccessI.write (b,0,nRead); 2^nws  
} ][YuJUK8  
catch(Exception e){e.printStackTrace ();} Der'45]*^  
} mX?t|:[b  
} XN{zl*`  
a:4!z;2 |  
i CB:p  
//打印回应的头信息 4Y4zBD=<  
public void logResponseHead(HttpURLConnection con) H^vA}F`  
{ 4$U^)\06W  
for(int i=1;;i++) &5[+p{2  
{ E]S:F3  
String header=con.getHeaderFieldKey(i); K$r)^K=s  
if(header!=null) 'Asr,[]?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @xBO[v  
Utility.log(header+" : "+con.getHeaderField(header)); <Q`3;ca^  
else \MPbG$ ^  
break; 2]FRIy d  
} tCPK_Wws?Z  
} "5?1S-Vl  
@gM}&G08  
xVN!w\0  
public void splitterStop() 3Wx\Liw,  
{ C@<gCMj,"  
bStop = true; #7}YSfm^6  
} FU.?n)P  
F[W0gjUc  
z+CX$.Z  
} <:mK&qu f  
<(yAat$H  
Q("4R  
/* `O;4 b#!g  
**FileAccess.java @P i]kWW})  
*//文件访问(定位,写)  3UKd=YsJ  
package NetFox; Q}a(vlZ  
import java.io.*; Z%=A[` 5]  
L]&y[/\E1  
;d_<6|*M  
public class FileAccessI implements Serializable{ <=w!:   
!4 lN[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4gWlSm)  
RandomAccessFile oSavedFile; Lw1[)Vk}E  
long nPos; VUz+ _)  
 o|#F@L3i  
#hMkajG  
public FileAccessI() throws IOException tF./Jx]_  
{ 9\=SG"e(  
this("",0); cqW(9A|8  
} ZPz=\^  
NzeiGj  
[;ZC_fD  
public FileAccessI(String sName,long nPos) throws IOException vF>]9sMv  
{ (A=Z,ed  
oSavedFile = new RandomAccessFile(sName,"rw"); $H]NC-\+>  
this.nPos = nPos; aygK$.wos  
oSavedFile.seek(nPos); cRNVqMpg  
} GdrVH,j  
S 2W@;XvV  
^\Q%VTM  
public synchronized int write(byte[] b,int nStart,int nLen) ZvO1=* J,  
{ ~`B]G  
int n = -1; {Ve`VV5E  
try{ pK"Z9y&  
oSavedFile.write(b,nStart,nLen); In+2~Jw/2!  
n = nLen; #^$_3A Y  
} F2EX7Crj  
catch(IOException e) s B^ejH  
{ ugTnz$  
e.printStackTrace (); "pH;0[r]  
} ?1] \3nj  
U}5]Vm$]  
D0TFC3.k}  
return n; dxtG3  
} 82?LZ?!PD  
@L0)k^:  
!(Q@1 c&z  
} >B*zzj  
~,xso0  
O'3/21)|y  
/* 0($On`#  
**SiteInfoBean.java 6E^9>  
*/ | qelvK*  
package NetFox; )ZFc5m^+u  
DnW/q  
&FYv4J  
public class SiteInfoBean { `~41>mM%  
&!M6{O=~  
Rtl 1eJ-  
private String sSiteURL; //Site's URL q(1hY"S"}b  
private String sFilePath; //Saved File's Path K]|hkp&  
private String sFileName; //Saved File's Name 3*(><<ZC  
private int nSplitter; //Count of Splited Downloading File a$bE2'cb  
+kD JZ  
+>$Kmy[3  
public SiteInfoBean() yUO%@;  
{//nSplitter的缺省值为5 Uty0mc(  
//default value of nSplitter is 5 t%f>*}*P*  
this("","","",5); sb?!U"v.'  
} Gm0}KU  
A:pD:}fm}D  
?.beN[X  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h|lH`m^  
{ kXlI *h  
sSiteURL= sURL; \|M[W~8  
sFilePath = sPath; ,Ik~E&Ku2'  
sFileName = sName; `@vksjxu  
this.nSplitter = nSpiltter; [~`p~@\+  
iU3PlF[B/o  
RUVrX`u*(  
} <p2\;\?4z  
l7IF9b$c  
2pP"dX  
public String getSSiteURL() >xsY"N&1i'  
{ s|TO9N)pO  
return sSiteURL; }"v#_vJfz7  
} %,aSD#l`f  
x{Dw?6TP  
'SrDc'?  
public void setSSiteURL(String value) ua_,c\iL  
{ q]SH'Wd  
sSiteURL = value; Z$6B}cz<  
} ];N/KHeZ  
PpF`0w=1%l  
av:%wJUl,$  
public String getSFilePath() ld 1[Usaq  
{ <JvYCWX`  
return sFilePath; cjd-B:l  
} S?VKzVDB.S  
2t>>08T  
~d ~oC$=TC  
public void setSFilePath(String value) d5R2J:dI  
{ %Q;:nVt  
sFilePath = value; ,\d03wha  
} eW}-UeT  
F6:LH,~8   
pigu]mj  
public String getSFileName() If8 ^  
{ wu b7w#  
return sFileName; Be<bBKQb  
} `49!di[  
3Ljj|5.q  
^BW8zu@=O  
public void setSFileName(String value) wgq=9\+&  
{ wnQi5P+  
sFileName = value; s*eM}d.p  
} ")nKFs5  
%/hokyx  
R$+"'N6p  
public int getNSplitter() 'GO *6$/  
{ ,Z7Ky*<j  
return nSplitter; Fx)><+-  
} VD =f 'D  
#c'}_s2F[  
aQzmobleep  
public void setNSplitter(int nCount) {BJH}vV1)  
{ #Pg?T%('`  
nSplitter = nCount; |It{L0=U  
} !d[]Qt%mA  
} rhGB l`(B  
t^%)d7$  
s:z  
/* _)4zm  
**Utility.java BIg2`95F|  
*/ x@pzgqi3  
package NetFox; #]^M/y h  
s5MG#M 9  
'RNj5r  
public class Utility { &lxMVynL  
KxfH6:\RB  
9C5F#(uY  
public Utility() ^W^Y"0y9`  
{ ?iHcY,  
yBv4 xKMH  
NL!xk cXO  
} 0TiDQ4}i[  
z: )*Aobwv  
//线程睡眠 Q^?$2ck=  
public static void sleep(int nSecond) {?X +Yw  
{  ;CV'  
try{ Z 8GIZ  
Thread.sleep(nSecond); w[EEA_\  
} ^?0?*  
catch(Exception e) %(s2{$3  
{ ma"M?aM  
e.printStackTrace (); A v;NQt8ut  
} dKw[#(m5v  
} %uo#<Ny/ I  
c^5fhmlt  
//日志 twaH20  
public static void log(String sMsg) 2&AX_#P  
{ P;|63" U  
System.err.println(sMsg); V=Bmpg  
} i=fhK~Jd  
wGHVq fm5  
^a!oq~ZSy  
public static void log(int sMsg) ?3v-ppw%  
{ sp0_f;bC  
System.err.println(sMsg); ?;w\CS^Qu  
} I^D*) z   
} f&&Ao  
C?6q ]k]r  
-:b<~S[  
/* 'l-VWqR-  
**TestMethod.java ?4Rq +  
*/ LVL#qNIu  
package NetFox; : >$v@d  
(?.h<v1}  
EvA8<o  
public class TestMethod { " ;\EU4R  
+hH7|:JQ  
&@PAv5iNf  
public TestMethod() A!$sO p  
{ ///xx/weblogic60b2_win.exe j1ap,<\.k  
try{ 90wnwz  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s;tI?kR>%  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DnF|wS  
SiteFileFetch fileFetch = new SiteFileFetch(bean); -YipPo"a  
fileFetch.start(); 0-d&R@lX.  
} 1d&Q E\2}  
catch(Exception e){e.printStackTrace ();} 0zA:?}  
C"k]U[%{  
kkj_k:Eah  
} (YYwn@NGj  
W)Yo-%  
V<KjKa+sG  
public static void main(String[] args) Xxm7s S  
{ V:AA{<  
new TestMethod(); ^[ 2siG  
} ]Rmu +N|  
} :/}=s5aQl/  
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