http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]a/'6GbR
} GZ8:e3ri
for(int i=0;i<nEndPos.length-1;i++) I7mG/
{ <zfKC
nEndPos = nStartPos[i+1]; F_ljx
} (M`|'o!
nEndPos[nEndPos.length-1] = nFileLength; Ror2qDF
} LC-)'Z9}5
} (vQ+e
U:|H9+5
J&6:d
//启动子线程 Gzm$OHbn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o~C('1Fdb
for(int i=0;i<nStartPos.length;i++) U CY2]E
{ )#`H."Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =nVmthGw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6vp0*ww
nStartPos,nEndPos,i); H?U't 09
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9$O@`P\
fileSplitterFetch.start(); \FifzKA
} DJP6TFT&G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fe$/t(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @ls.&BHUP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jO)&KEh
nEndPos = " + nFileLength); daX*}Ix
// fileSplitterFetch[nPos.length-1].start(); 1r571B*O
cwynd=^nC
%EI<@Ps8c
//等待子线程结束 k^%_V|&W/(
//int count = 0; j>'B[
//是否结束while循环 ZnXejpj)D
boolean breakWhile = false; N[k<@Q?*a
vv/J 5#^,\
7co`Zw4}g
while(!bStop) d^84jf.U
{ OD+5q(!"a
write_nPos(); 8(xw?|D7
Utility.sleep(500); G|9B)`S
breakWhile = true; a$}mWPp+f
W9R`A
o^ h(#%O
for(int i=0;i<nStartPos.length;i++) _V@P-Ye
{ #WufZ18#
if(!fileSplitterFetch.bDownOver) qY(:8yC36
{ T9)wj][ .
breakWhile = false; ,7,;twKz
break; 9*}gl3y
} ,{{SI
} dr})-R
if(breakWhile) o&-L0]i|
break; T-8J
77Q}=80GU;
xmH-!Da
//count++; \G;CQV#{9
//if(count>4) 7g6RiH}
// siteStop(); 59!)j>f
} fLB1)kTS
77We;a
.3wY\W8Dr-
System.err.println("文件下载结束！"); o3h-=t
} kx{!b3"
catch(Exception e){e.printStackTrace ();} q)iTn)Z!
} X?dfcS*!n
|}S1o0v{(a
R^8B3-aA`
//获得文件长度 ^ KH>1!
public long getFileSize() DQgH_!
{ h<3p8eB
int nFileLength = -1; P s#>y&
try{ kO ![X^V
URL url = new URL(siteInfoBean.getSSiteURL()); R&So4},B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3g'+0tEl
httpConnection.setRequestProperty("User-Agent","NetFox"); a%K}j\M
~_PYNY`"
QIAR
int responseCode=httpConnection.getResponseCode(); D ,M@8h,
if(responseCode>=400) M|%c(K#E,3
{ |.w;r
processErrorCode(responseCode); 8(A{;9^g
return -2; //-2 represent access is error uO'/|[`8
} ,sDr9h/'C3
xzk}[3P{
z="L4
String sHeader; $D_HZ"ytu
JR1*|u
uva\0q
for(int i=1;;i++) E`)Qs[?Gk
{ dlD}Ub
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :p-Y7CSSu
//Utility.log(in.readLine()); - ]Y wl
sHeader=httpConnection.getHeaderFieldKey(i); 6k9LxC:M
if(sHeader!=null) UqtHxEI%R~
{ /`+7_=-
if(sHeader.equals("Content-Length")) *K)0UKBr
{ ~:2K#q5C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8:{q8xZ=k
break; tWk{1IL
} zM59UQU;
} .#!mDlY;
else ,- HIFbXx@
break; (I=6Nnt'
} `-O=>U5nH
} MsjnRX:c3u
catch(IOException e){e.printStackTrace ();} #&siHHs \
catch(Exception e){e.printStackTrace ();} zilaP)5x6
4}-#mBV]/
og-]tEWA1
Utility.log(nFileLength); -1W
yXF|Sqv
&r@H(}$1\
return nFileLength; j'Wp
} SE!L :
e1P7 .n}
-,GEv%6c
//保存下载信息（文件指针位置） E1W:hGI
private void write_nPos() c{>|o
{ (6k>FSpg
try{ \_ -DyD#3
output = new DataOutputStream(new FileOutputStream(tmpFile)); p@tp]u`7
output.writeInt(nStartPos.length); re uYTH
for(int i=0;i<nStartPos.length;i++) ~zyQ('
{ RWikJ
// output.writeLong(nPos); `d*b]2
output.writeLong(fileSplitterFetch.nStartPos); ,!>fmU`E4
output.writeLong(fileSplitterFetch.nEndPos); 6V;:+"BkJ
} :6u~aT/
output.close(); kF-TG3
} :`J>bHE
catch(IOException e){e.printStackTrace ();} ORH93`
catch(Exception e){e.printStackTrace ();} !}q."%%J_%
} rzV"Dm$'
7bT /KLU
J@` 8(\(
//读取保存的下载信息（文件指针位置） DHzkRCM
private void read_nPos() 7;xKy'B\
{ q\H7&w
try{ 1+^n!$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $L&BT 0
int nCount = input.readInt(); AbZ:(+@cP
nStartPos = new long[nCount]; %6]\^
nEndPos = new long[nCount]; 4oJ$dN
for(int i=0;i<nStartPos.length;i++) U**)H_S/~
{ Nza; O[
nStartPos = input.readLong(); 0yTQ{'Cc
nEndPos = input.readLong(); QUp?i
} *<k&#D"m
input.close(); O+FBQiv
} N84qcc
catch(IOException e){e.printStackTrace ();} {^wdJZ~QLK
catch(Exception e){e.printStackTrace ();} PYieD}'
} RbAt3k;y
J wFned#T
o?dR\cxj
private void processErrorCode(int nErrorCode) la702)N{
{ PP-kz;|
System.err.println("Error Code : " + nErrorCode); xt))]aH
} >zR14VO`_|
q{@P+2<wF
XnA6/^
//停止文件下载 8.2`~'V
public void siteStop() w_H2gaQ
{ 3{pk5_c
bStop = true; x@Vt[}e
for(int i=0;i<nStartPos.length;i++) (UcFNeo
fileSplitterFetch.splitterStop(); tgW kX
/e<5Np\X
6 [ _fD
} 4:3_ER]J
} GZ"/k<~0
//负责部分文件的抓取 CWvlr nv
**FileSplitterFetch.java n?Zf/T
*/ Y)OBTX
package NetFox; M5u_2;3
[R\=M'
|."G?*
import java.io.*; h0XH`v
import java.net.*; Bb_Q_<DTs
LP?P=c
_H2tZ%RM
public class FileSplitterFetch extends Thread { I-{^[pp
%^!aB
H;wR
String sURL; //File URL >{F!ntEj
long nStartPos; //File Snippet Start Position os_WYQ4>j
long nEndPos; //File Snippet End Position zn^v!:[
int nThreadID; //Thread's ID O+vcs4
boolean bDownOver = false; //Downing is over OQc{ V
boolean bStop = false; //Stop identical {? 2;0}3?;
FileAccessI fileAccessI = null; //File Access interface N(BiOLZL6
j%5a+(H,z;
x~Cz?ljbn
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Um'Ro4
{ q_pmwJ:UL
this.sURL = sURL; o}W;Co
this.nStartPos = nStart; ',#
this.nEndPos = nEnd; J% AG`
nThreadID = id; idz9YpW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BPiiexTV9
} E[*0Bo]
7vq DZg
Z>h{` X\2
public void run() yDuq6`R*
{ Pl?}>G
while(nStartPos < nEndPos && !bStop) vG3M5G
{ ki4Xp'IK
< GU
Of&"U/^
try{ ?V?<E=13
URL url = new URL(sURL); yF;?Hg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o"4E+1qwM
httpConnection.setRequestProperty("User-Agent","NetFox"); L}b'+Wi@
String sProperty = "bytes="+nStartPos+"-"; b?>VPuyBb
httpConnection.setRequestProperty("RANGE",sProperty); )r pD2H
Utility.log(sProperty); `/c@nxh
I3An57YV].
M#T#:wf~
InputStream input = httpConnection.getInputStream(); qzHU)Ns(_
//logResponseHead(httpConnection); ~.H~XKw
*F..ZS'$[
7P c(<Ui+
byte[] b = new byte[1024]; {yU0D*#6
int nRead; jf8w7T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kAt RY4p
{ GqMB^Ad
nStartPos += fileAccessI.write(b,0,nRead); X7b!;%3@
//if(nThreadID == 1) S!<"Swf:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wO89&XZ<
} )tCx5 9
Yu;9&b
.=CH!{j
Utility.log("Thread " + nThreadID + " is over!"); B/rzh? b
bDownOver = true; N:7.:Yw
//nPos = fileAccessI.write (b,0,nRead); [lZ=s[n.
} }Wqtip:L
catch(Exception e){e.printStackTrace ();} n@_)fFD%
} IOS^|2:,
} _C5nApb
e]Puv)S>{8
x?gQ\0S<
//打印回应的头信息 m'c#uU
public void logResponseHead(HttpURLConnection con) d#4Wj0x
{ .}`V I`z*
for(int i=1;;i++) h*l cEzG?A
{ VH[l\I(h
String header=con.getHeaderFieldKey(i); 0yKhp:^
if(header!=null) C,(j$Id
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2zM-Ob<U`
Utility.log(header+" : "+con.getHeaderField(header)); i!tc
else y{?Kao7Ij
break; N?zV*ngBS
} @??u})^EL
} OFp#<o,p
$8=(I2&TW
my]P_mE
public void splitterStop() hj+p`e S
{ q{[1fE"[K4
bStop = true; wzg i @i
} K` 2i
16L"^EYq
Vl-D<M+ih
} ;tm3B2
zWJKYFqK
Ls(&HOK[p
/* 8z?$t-DO
**FileAccess.java mcCB7<. e
*//文件访问(定位，写) X:DMT>5k
package NetFox; UYH|?Jw!N
import java.io.*; 4I z.fAw
M.X}K7Z_/
t6j-?c('
public class FileAccessI implements Serializable{ [@x
t&38@p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $4sAnu]
RandomAccessFile oSavedFile; 80dSQ"y
long nPos; OW?uZ<z
>=bt
X,&`WPA:S
public FileAccessI() throws IOException 0,bt^a
{ V,E9Uds
this("",0); *Gf&q
} y)0gJP L^
:J<Owh@
8qn{
public FileAccessI(String sName,long nPos) throws IOException g~eJ YS,
{ %s]U@Ku(a
oSavedFile = new RandomAccessFile(sName,"rw"); dP?nP(l
this.nPos = nPos; .[#xQ=9`
oSavedFile.seek(nPos); K6ciqwUO
} YcPKM@xo
\m@]G3=]
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public synchronized int write(byte[] b,int nStart,int nLen) D\@e{.$MZ|
{ $#D n4
int n = -1; cn@03&dAl
try{ c]S+70!n
oSavedFile.write(b,nStart,nLen); U<K|jsFo
n = nLen; 7?+5%7-
} ^tQPJ
catch(IOException e) cPV5^9\T
{ N|bPhssFw
e.printStackTrace (); r4;^c}
} "0!~g/X`rK
dBsRm{aS
*sjj"^'=
return n; HI}pX{.\
} ,G/\@x%
]r"31.w(
z]'|nX
} -$'~;O3s
3csm`JVK
B?$S~5 }
/* +ZY2a7uI
**SiteInfoBean.java b5lk0jA
*/ &8pCHGmV)
package NetFox; <)r,CiS
0*/mc96
(xI)"{
public class SiteInfoBean { <\B],M1=s=
VaOpO8y`
AN|jFSQ'
private String sSiteURL; //Site's URL 4he v ;
private String sFilePath; //Saved File's Path Z&AHM &,yj
private String sFileName; //Saved File's Name Np|:dP9#}
private int nSplitter; //Count of Splited Downloading File 6-)7:9y
=x|##7
!l sy&6
public SiteInfoBean() Oz"@yL}
{//nSplitter的缺省值为5 #j(q/ T{x
//default value of nSplitter is 5 tI/mE[W
this("","","",5); x.jYip
} ls8olLM>
e[d7UV[Knn
Zkwy.Hq^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2+c>O%L
{ M Ak-=?t
sSiteURL= sURL; .=.yZ
sFilePath = sPath; {hkM*:U
sFileName = sName; s!8J.hD'I
this.nSplitter = nSpiltter; Dme(Knly
Co{MIuL
Xq=!"E
} z&>9 s)^-
X67C;H+
'6Pu[^x
public String getSSiteURL() =:t@;y
{ +G3nn!gl4
return sSiteURL; sR7{i
} l8hvq(,{
.FfwY 'V
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public void setSSiteURL(String value) ~frPV8^DP
{ [[Jv)?jm
sSiteURL = value; +X2 i/}
} k1QpX@
/xX,
i_oro"%yL
public String getSFilePath() ;-Y]X(z>
{ mh!N^[=n
return sFilePath; g:~?U*f-
} ZNL;8sI?>
*@$($<pY&
#z-iL!?
public void setSFilePath(String value) qd#(`%_/
{ ]yj4~_&O
sFilePath = value; #Tgz,e9
} (Fbm9(q$d
} K+Q9<~u
hJ$C%1;
public String getSFileName() jm#F*F vL
{ Q G=-LXv:@
return sFileName; MA/"UV&M(
} VOowA^
!}Woo$#ND
Se;?j-
public void setSFileName(String value) e"v[)b++Y
{ 5'{qEZs^QU
sFileName = value; :*F3
} &kXGWp
V,|Bzcz
\>aa8LOe
public int getNSplitter() 5CRc]Q#@
{ &2<&X( )
return nSplitter; }Uqa8&
} N%n1>!X)!
KL:6P-3
c4qp3B_w
public void setNSplitter(int nCount) M'>D[5;N~
{ \M'bY:
nSplitter = nCount; m_r@t*
} Je4.9?Ch
} 5m%baf2_
Nw3I
=yhn8t7@]
/* N,sqrk]
**Utility.java OH!$5FEc
*/ vxzf[
package NetFox; E |GK3/
1K*f4BnDr~
fn?6%q,!ls
public class Utility { CwEWW\Bu
w ;s ]n
|Ad6~E+aL-
public Utility() gvRc:5B[
{ QU,TAO
&)"7am(S`
t7*H8
} Hq"<vp
_A~~L6C
//线程睡眠 v,!Y=8~9
public static void sleep(int nSecond) }G,SqpcG
{ @6i8RmOu}
try{ &=6cz$]z
Thread.sleep(nSecond); UVoLHd
} :UJUh/U
catch(Exception e) Fl'xmz^
{ #by9D&QP]
e.printStackTrace (); W:+2We@
} oX:1 qJrC
} ZimMjZ%4
13>3R+o
//日志 qeK
public static void log(String sMsg) tE9_dR^K
{ N`|Ab(.
System.err.println(sMsg); 13_+$DhU-L
} x4HMT/@AG2
.'NO~
G &rYz
public static void log(int sMsg) 4f*Ua`E_
{ p$b=r+1f
System.err.println(sMsg); thm3JfQt
} cJ(zidf_$
} 1R+)T'in
c^[1]'y
(zTI)EV
/* !MF"e|W
**TestMethod.java 2cX"#."5p
*/ O.up%'%,
package NetFox; HBga'xJ
Sfr\%Buv
X?}GPA4 W
public class TestMethod { BqEubP(si
W|-N>,G
@IyH(J],h
public TestMethod() p`l[cVQ<
{ ///xx/weblogic60b2_win.exe d`],l\oC
try{ _F/lY\vm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4pTuP /
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1~xn[acy
SiteFileFetch fileFetch = new SiteFileFetch(bean); { d2f)ra.
fileFetch.start(); |>o0d~s
} 6L6~IXL>
catch(Exception e){e.printStackTrace ();} ^p-e
<sWcS; x
@tv];t
} 8hdAXWPn
{@K2WB
xMfv&q=k@
public static void main(String[] args) b=QGbFf
{ ";Ig%]
new TestMethod(); #ZnX6=;X
} xV 1Z&l
} )Fr;'JYC1S
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