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http断点续传简单实现(java)

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/* ~i}/  
**SiteFileFetch.java tfe'].uT  
*/ Z@Qf0 c  
package NetFox; 2"Y=*s  
import java.io.*; 8R;E+B{  
import java.net.*; BMhuM~?(  
#`"B YFV[E  
;:Kc{B.s  
public class SiteFileFetch extends Thread { Mq6_Q07  
`]Vn[^?D  
EkN>5).  
SiteInfoBean siteInfoBean = null; //文件信息Bean gJzS,g1]  
long[] nStartPos; //开始位置 kaCn@$  
long[] nEndPos; //结束位置 W*4!A\K  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 qEjsAL  
long nFileLength; //文件长度 CR|>?9V  
boolean bFirst = true; //是否第一次取文件 Ax!fvcsN  
boolean bStop = false; //停止标志 O}7aX '  
File tmpFile; //文件下载的临时信息 8}^ym^H|j  
DataOutputStream output; //输出到文件的输出流 ]08~bL1Q  
27H4en; o=  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9AQ2FD  
public SiteFileFetch(SiteInfoBean bean) throws IOException } x'o`GuUf  
{  +!wkTrV  
siteInfoBean = bean; 8EI&}I  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Z,b^f Vw  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); a &R,jq  
if(tmpFile.exists ()) HMR!XF&JjC  
{ 8ZO~=e  
bFirst = false; W8!8/ IZbN  
read_nPos(); lx~mn~;x  
} UX'tdB !A  
else @gJPMgF$F  
{ Szlww  
nStartPos = new long[bean.getNSplitter()]; _LZ 442  
nEndPos = new long[bean.getNSplitter()]; .MRLA G  
} iWn7vv/t  
It^_?oiK  
F=kiYa}  
sZU Ao&  
} tLx8}@X"  
]}A yDy6C  
v8A{ q  
public void run() DAd$u1  
{ 9, 792b  
//获得文件长度 11yS2D   
//分割文件 u+8?'ZT,  
//实例FileSplitterFetch g|4v>5Y  
//启动FileSplitterFetch线程 Al]z =  
//等待子线程返回 n L!nzA  
try{ c1_?Z  
if(bFirst) {*4Z9.2c*  
{ _n< @Jk~  
nFileLength = getFileSize(); 9}Zi_xK&|e  
if(nFileLength == -1) E}=F   
{ ~3m} EL  
System.err.println("File Length is not known!"); &oiBMk`*  
} z[_Gg8e  
else if(nFileLength == -2) YA^g[,  
{ ,[Z;"wE  
System.err.println("File is not access!"); knZ<V%/e  
} 1uhSP!b  
else :y[tZ&*<_?  
{ Q|cA8Fn  
for(int i=0;i<nStartPos.length;i++) oI%.oP}G  
{  \R<OT%8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8f|+045E@  
} MT@Uu  
for(int i=0;i<nEndPos.length-1;i++) SkA"MhX  
{ 93#wU})  
nEndPos = nStartPos[i+1]; &Lgi  
} MMUw+jM4  
nEndPos[nEndPos.length-1] = nFileLength; #Y<b'7yJ  
} JTB5#S4W  
} ]dIr;x`  
:J+GodW  
K3t^y`z  
//启动子线程 uM~j  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .](s\6'  
for(int i=0;i<nStartPos.length;i++) D$c4's `5  
{ S-+^L|  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l,3[hx  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5bKn6O)K  
nStartPos,nEndPos,i); Ss7XjWP.}  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *,DBRJ_*7  
fileSplitterFetch.start(); -n~VMLd?@  
} 1{S" axSL  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -vC?bumR%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }' t*BaU  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Djf,#&j!3  
nEndPos = " + nFileLength); OC[(Eq  
// fileSplitterFetch[nPos.length-1].start(); 2]*2b{gF,  
{z}OZHJN  
) 4'@=q  
//等待子线程结束 \D #NO  
//int count = 0; g@lAk%V4  
//是否结束while循环 /P|jHK|{  
boolean breakWhile = false; FeFH_  
"$BWP  
z<mU$<  
while(!bStop) [(N<E/m%B  
{ Wc$1Re{z  
write_nPos(); Ie?C<(8Ul  
Utility.sleep(500); Z`b{r;`m8  
breakWhile = true; ^T|~L<A3  
<tg>1,C  
%/&?t`%H  
for(int i=0;i<nStartPos.length;i++) &6 L{1  
{ I(Yyg,1Z  
if(!fileSplitterFetch.bDownOver) YvK8;<k@-?  
{ ?79ABm a  
breakWhile = false; Tce2]"^;  
break; `D%bZ%25c  
} lU.@! rGbw  
} U{o0Posg  
if(breakWhile) Hd)4_ uBt  
break; dLm~]V3  
=6TD3k6(2  
L%JmdY;  
//count++; ( Qw"^lE3  
//if(count>4) dg1h<]T"9  
// siteStop(); .Eg>)  
} u#Qd `@p  
Ro?a DrQ  
b#^UP  
System.err.println("文件下载结束!"); ; ,]T|> M  
} .~6p/fHX  
catch(Exception e){e.printStackTrace ();} DO$jX 4  
} Dw^d!%Ala  
]|[oL6"  
o84!$2P+w  
//获得文件长度 ;p#)z/zZ  
public long getFileSize() >LwZ"IE V  
{ T)]5k3{  
int nFileLength = -1; q8.K-"f(Q  
try{ MD S;qZx=  
URL url = new URL(siteInfoBean.getSSiteURL()); *#,wV  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jx@3zl  
httpConnection.setRequestProperty("User-Agent","NetFox"); Nq)=E[$  
-lm\~VZT3  
T'l >$6  
int responseCode=httpConnection.getResponseCode(); {ls$#a+d  
if(responseCode>=400) QOkPliX  
{ -Vk+zEht  
processErrorCode(responseCode); nqt;Ge M  
return -2; //-2 represent access is error &V[m{.  
} q7C>A`w  
XU .FLNe  
WLEjRx  
String sHeader; uHUicZf.  
%J?;@ G)r  
k#% BxT  
for(int i=1;;i++) [MYd15  
{ <IGQBu#ZH  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h \b]>q@  
//Utility.log(in.readLine()); B]q &?~  
sHeader=httpConnection.getHeaderFieldKey(i); Ym5q#f)|  
if(sHeader!=null) { D1.  
{ T2 0dZ8{y  
if(sHeader.equals("Content-Length")) ]C-hl}iq  
{ ]%3o"|  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g6k@E,cI_  
break; YsXP$y]g-  
} z{cIG8z  
} ]n0kO&  
else vW 0m%  
break; b,8W |  
} Pm6/sO  
} lN)U8  
catch(IOException e){e.printStackTrace ();} cejSGsW6q  
catch(Exception e){e.printStackTrace ();} C XZm/^  
n0kBLn  
-82Rz   
Utility.log(nFileLength); q3B#rje>h  
 [ottUS@  
&)OX*y  
return nFileLength; H3}{]&a  
} 0x'>}5`5  
?ZDXT2b~~  
pm,&kE  
//保存下载信息(文件指针位置) ,L^eD>|j5  
private void write_nPos() b;O]@kBB  
{ k`6T% [D]  
try{ ? r=cLC  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )R+@vh#Q<$  
output.writeInt(nStartPos.length); W\o(f W  
for(int i=0;i<nStartPos.length;i++) xXM`f0s@+]  
{ ]QM6d(zDA  
// output.writeLong(nPos); )Fk%, H-1  
output.writeLong(fileSplitterFetch.nStartPos); `9Zoq=/  
output.writeLong(fileSplitterFetch.nEndPos); 0Np }O=>  
} 9`+c<j4/B  
output.close(); Uwr inkoeE  
} I|,^a|\  
catch(IOException e){e.printStackTrace ();} 2GA6@-u\  
catch(Exception e){e.printStackTrace ();} V=BF"S;-'  
} ~S15tZ $  
.HF+JHIUu  
%p)6m 2Sb  
//读取保存的下载信息(文件指针位置) |j$&W;yC  
private void read_nPos() IY?[0S  
{ gR"'|c   
try{ bWo-( qxq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); a;D{P`%n  
int nCount = input.readInt(); ~sshhuF  
nStartPos = new long[nCount]; /cUcfe#X  
nEndPos = new long[nCount]; (X@JlAfB  
for(int i=0;i<nStartPos.length;i++) 0: R}  
{ 0F6^[osqtl  
nStartPos = input.readLong(); h #Od tc1)  
nEndPos = input.readLong(); y.26:c(  
} =O1N*'e  
input.close(); ngj=w;7~+  
} k!b\qS~Q  
catch(IOException e){e.printStackTrace ();} Mb=vIk{B f  
catch(Exception e){e.printStackTrace ();} n;)!N  
} | Uf6k`  
sptDzVM  
;(fDR8  
private void processErrorCode(int nErrorCode) >XjSVRO  
{ RxY ;'NY  
System.err.println("Error Code : " + nErrorCode); 3'8B rK  
} *+re2O)Eh'  
e3UGYwQ  
x'@0]f.  
//停止文件下载 tbF>"?FY/  
public void siteStop() Nt9M$?\P  
{ A1zM$ wDU  
bStop = true; *x2+sgSf_0  
for(int i=0;i<nStartPos.length;i++) |X k'd@<  
fileSplitterFetch.splitterStop(); _>%P};G{>  
2i*-ET  
@*e|{;X]hy  
} S)of.Nq.;  
} 3t5`,R1@t  
//负责部分文件的抓取 u;p{&\(]  
**FileSplitterFetch.java s3kHNDdC  
*/ ;3OQgKI  
package NetFox; YwyP+S r\  
~UX@%0%)N  
(wU<Kpt?J  
import java.io.*; B> *zQb2:  
import java.net.*; O%;H#3kn&s  
%eB0 )'  
y{+$B Y$_  
public class FileSplitterFetch extends Thread { :2iNw>z1  
,3 &XV%1  
X@|'#%  
String sURL; //File URL 2%i_SX[  
long nStartPos; //File Snippet Start Position G=/a>{  
long nEndPos; //File Snippet End Position a7s+l=  
int nThreadID; //Thread's ID l5QH8eNwME  
boolean bDownOver = false; //Downing is over x7)j?2  
boolean bStop = false; //Stop identical Yb\t0:_  
FileAccessI fileAccessI = null; //File Access interface wl1i @&9  
htX;"R&  
DW&%"$2  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CRf!tsj@  
{ F]DRT6)  
this.sURL = sURL; iZ % KHqG  
this.nStartPos = nStart; "{1`~pDj?  
this.nEndPos = nEnd; 8TGO6oY+=  
nThreadID = id; V TQ V]>|  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A5cx!h  
} . >[d:0  
cih@: =Qy  
|VxEW U/  
public void run() VI7f}  
{ )Kkw$aQI"d  
while(nStartPos < nEndPos && !bStop) Dn~r~aR$g  
{ G66sP w  
"S)2<tV  
<qjNX-|  
try{ @q:v?AO  
URL url = new URL(sURL); /8(c^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); / RU'~(  
httpConnection.setRequestProperty("User-Agent","NetFox"); qpzzk9ba[  
String sProperty = "bytes="+nStartPos+"-"; GSo&$T;B6  
httpConnection.setRequestProperty("RANGE",sProperty); l]t9*a]a  
Utility.log(sProperty); jN 9|q  
"&;8U.  
n "?It  
InputStream input = httpConnection.getInputStream(); ,(&jG^IpVJ  
//logResponseHead(httpConnection);  uyBmGS2  
IlQNo 1  
ATx6YP@7~  
byte[] b = new byte[1024]; mOgsO  
int nRead; &AM<H}>  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7R9.g6j  
{ p|fSPSz  
nStartPos += fileAccessI.write(b,0,nRead); &c!d}pU}  
//if(nThreadID == 1) 8axz`2`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !-%fCg(B  
} I3sH8/*  
gwVfiXR4  
wMFo8;L  
Utility.log("Thread " + nThreadID + " is over!"); n[DQ5l  
bDownOver = true; & D@/_m $  
//nPos = fileAccessI.write (b,0,nRead); n.9k<  
} vC$Q4>m  
catch(Exception e){e.printStackTrace ();} qZw4"&,j$  
} 74f3a|vx/  
} 0-Z sV3I&  
)Dn~e#  
V)x(\ls]SX  
//打印回应的头信息 qkQ _#  
public void logResponseHead(HttpURLConnection con) E.~;  
{ a(Q4*XH4  
for(int i=1;;i++) =2+';Xk\  
{ 81?7u!=ic+  
String header=con.getHeaderFieldKey(i); x~1.;dBF  
if(header!=null) F>N3GPRl  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kg@D?VqJP  
Utility.log(header+" : "+con.getHeaderField(header)); x1H?e8  
else <3?T^/8  
break; Ce&nMgd~  
} o=/Cje  
} Twqkd8[  
! C}t)R]^  
^Ej4^d  
public void splitterStop() /P_1vQq  
{ dzA5l:5  
bStop = true; IX/FKSuq  
} $BIQ# T>qK  
W?+U%bIZ9  
?t;>]Wo;  
} Xxl>,QUA  
)HZUCi/F]  
\=n0@1Q=>  
/* O<}^`4d  
**FileAccess.java /WIO@c  
*//文件访问(定位,写) Z)iRc$;  
package NetFox; r]!<iw  
import java.io.*; 7\.Ax  
PT2b^PP  
kk`BwRh)d;  
public class FileAccessI implements Serializable{ ,$;g'z!N  
m]g"]U:  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oECM1'=Bf  
RandomAccessFile oSavedFile; aFkxR\x 6%  
long nPos; *7 L*:g  
/ D9FjOP  
Rg:3}T`~n  
public FileAccessI() throws IOException XBJ9"G5  
{ R<r"jOd]  
this("",0); L,@O OBD  
} c k~gB  
i?7%z`  
{HgW9N(  
public FileAccessI(String sName,long nPos) throws IOException re.%$D@  
{ s3G\L<~mB  
oSavedFile = new RandomAccessFile(sName,"rw"); = mn jIp  
this.nPos = nPos; m~K[+P  
oSavedFile.seek(nPos); HSt|Ua.c/h  
} kBPFk t2  
m7:E7 3:  
Salu[)+?  
public synchronized int write(byte[] b,int nStart,int nLen) [\9WqHs  
{ E\M{/.4 4  
int n = -1; DNgQ.lV  
try{ xx}R6VKU.  
oSavedFile.write(b,nStart,nLen); " mKMym2  
n = nLen; x,9fOA  
} eYL7G-3  
catch(IOException e) uj.~/W1,!  
{ Lh=~3  
e.printStackTrace (); WY@x2bBi  
} 47Y| 1  
Q37VhScs  
K#"@nVWJ.m  
return n; ;O YwZ  
} E(G=~>P  
] =Js5  
//--r5Q  
} {$iJYS\  
(xU+Y1*g"%  
{Y5h*BD>  
/* _ Ko0  
**SiteInfoBean.java Isq3YY  
*/ 9Ao0$|@b  
package NetFox; mB(*)PwZ  
.js4)$W^  
-;$+`<%  
public class SiteInfoBean { UQ|zSalv,  
7YRDQjg  
=q|fe%#  
private String sSiteURL; //Site's URL uTJi }4cw  
private String sFilePath; //Saved File's Path D#%J||  
private String sFileName; //Saved File's Name QN(f8t(  
private int nSplitter; //Count of Splited Downloading File &%pB; dk  
#( nheL  
X$JO<@x  
public SiteInfoBean() K{VF_S:  
{//nSplitter的缺省值为5 BfOG e!Si  
//default value of nSplitter is 5  =erA.u  
this("","","",5); Vvx(7p-GQ  
} $"{V],:T |  
ADX}  
XA])<dZ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +DKrX  
{ |Y<ca   
sSiteURL= sURL; y? [*qnPj  
sFilePath = sPath; T[)) ful  
sFileName = sName; 0:G@a&Lr  
this.nSplitter = nSpiltter; 1at$_\{.(  
Fm}O,=  
81a&99k#  
} | -Di/.  
k;3P;@3,W  
~QdwoeaD  
public String getSSiteURL() hE:P'O1  
{ ;hs:wLVa"  
return sSiteURL; 6\86E$f=h  
} 'OGOT0(  
PqcuSb6  
Tu_dkif'  
public void setSSiteURL(String value) OxF\Hm)(  
{ ZNB*Azi  
sSiteURL = value; +2oZB]GPL  
} 9BANCW"  
^J>28Q\S  
~E^EF{h   
public String getSFilePath() gx[#@ (  
{ M;MD-|U  
return sFilePath; _| 8"&*T^  
} *Oz5I  
| 7>1)  
RA[` Cp"  
public void setSFilePath(String value) }VR&*UJE  
{ w & RpQcV  
sFilePath = value; mQ%kGqs  
} 9+QLcb  
NtTLvO6  
=mqV&FgRo  
public String getSFileName() !^axO  
{ l^`!:BOtR  
return sFileName; &s/aJgJhp  
} ?5mVC]W?]  
^Hq}9OyS9  
kq%`9,XE  
public void setSFileName(String value) 6}NvVolr  
{ GWE`'V  
sFileName = value; x6DH0*[.  
} =hl-c  
f| N(~  
mA^>Y_:  
public int getNSplitter() y6*i/3  
{ =r0!-[XCa  
return nSplitter; 5!nZvv  
} @oRYQ|.R  
,A6*EJ\w   
z5'VsK:  
public void setNSplitter(int nCount) WgPL4D9=  
{ 3C,e>zE}  
nSplitter = nCount; b}"/K$`Fd  
} N=I5MQG  
} i0AC.]4e"  
R&xD|w8UjM  
Jy|Mfl%d  
/* .j&jf^a5  
**Utility.java 2:DpnLU5  
*/ C)C;U&Qd  
package NetFox; Kv#daAU  
aRG[F*BY  
P`bR;2o  
public class Utility {  L<QDC   
n@mUQ6  
_)Qt,$  
public Utility() bfpW ^y  
{ xBw"RCBz^  
*Mp<4B  
U'lmQrF!  
} df J7Dhn  
Ej34^*m9k  
//线程睡眠 a|s=d  
public static void sleep(int nSecond) [\.>BK  
{ gdG: &{|x  
try{ ))KsQJ"V  
Thread.sleep(nSecond); 8dZH&G@;  
}  zIAMM  
catch(Exception e) 15eHddd  
{ l%w7N9  
e.printStackTrace (); z:fhq:R(  
} U_8I$v-~  
} }bnkTC  
X r)d;@yi  
//日志 pH~JPNng  
public static void log(String sMsg) gRqz8UI  
{ {W4t]Ff  
System.err.println(sMsg); {(MG: B  
} SQ1&n;M}f  
sIy$}_  
AMm O+E?  
public static void log(int sMsg) #&5\1Qu  
{ r=[}7N  
System.err.println(sMsg); 9=}/t9k  
} /6.b>|zF  
} JWdG?[$  
/nmfp&@  
mn4;$1~e>H  
/* ut,"[+ J  
**TestMethod.java L%8"d6  
*/ plIx""a^h  
package NetFox; 'K"*4B^3  
p-6.:y  
*oWzH_  
public class TestMethod { =N0cz%  
=~S   
o{Ep/O`  
public TestMethod() uJ y@  
{ ///xx/weblogic60b2_win.exe vVf!XZF  
try{ )/pPY  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]s S oIT  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2M1mdkP3  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ky%%H;  
fileFetch.start(); .R"L$V$RU.  
} X5yhS  
catch(Exception e){e.printStackTrace ();} K;ML'  
E4.IS =4S  
n)H0;25L  
} ;(,Fe/wvC  
a RwBxf  
'ng/A4  
public static void main(String[] args) Bx)&MYY}[[  
{ 4%7*tVG  
new TestMethod(); 4>HGwk@+8  
} sP |i '  
} $ g^;*>yr  
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