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)); QlnI&o
} $=!_ !tr
for(int i=0;i<nEndPos.length-1;i++) OLJ|gunA#
{ H1ox>sC
nEndPos = nStartPos[i+1]; UDgUbi^v|D
} G$iC@,/
nEndPos[nEndPos.length-1] = nFileLength; V(!-xu1,
} )K0rPnYV
} 8{%[|Ye
?h-:,icR
$2v{4WP7G
//启动子线程 ftqeiZ 2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fXx !_Z
for(int i=0;i<nStartPos.length;i++) 2$> <rB
{ tb'O:/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z-'xJq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "&TN}SBW
nStartPos,nEndPos,i); wn>?r ?KIB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lDtl6r/
fileSplitterFetch.start(); )cRP6 =
} 1NU@k6UHl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }ILg_>uq[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $s9YU"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "xMnD(p
nEndPos = " + nFileLength); ,uhOf! |
// fileSplitterFetch[nPos.length-1].start(); zqGo7;;#
uRRp8hht
$mDlS
//等待子线程结束 OO?BN!
//int count = 0; _Dg|Iz,Uh
//是否结束while循环 Pu0O6@Rg
boolean breakWhile = false; I(0 *cWO
a*UxRi8
!L55S03
while(!bStop) )tR@\G>%
{ sy+tLDMd
write_nPos(); %1PNP<3r0
Utility.sleep(500); :J;*]o:
breakWhile = true; {$qLMx';
+m1y#|08
v^Pjvv=
for(int i=0;i<nStartPos.length;i++) LLW\1 cxi
{ r|0wIpi6Q
if(!fileSplitterFetch.bDownOver) :"~n` Q2[
{ C1SCV^#
breakWhile = false; $n9Bp'<
break; {-e|x&-
} KIHr%
} ^@AIXBe
if(breakWhile) ]c$)0O\O
break; 0X4%Ccs
[<A|\d'x
QMWDII&t
//count++; 4A~1Z,"%v(
//if(count>4) S,2{^X
// siteStop(); A\};^Y
} &0%x6vea
LIMPWw g
^Y+P(o$HM
System.err.println("文件下载结束！"); vvcA-k?
} 85]3y%f9
catch(Exception e){e.printStackTrace ();} j21nh>d
} HD{2nZT
VF] ~J=>i
^,N=GZRWW
//获得文件长度 dG*2-v^G
public long getFileSize() ~jn~M_}K
{ 4ROuy+Ms'
int nFileLength = -1; Q\[2BJo/
try{ 8k -l`O~
URL url = new URL(siteInfoBean.getSSiteURL()); ^Jdji:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ' lMPI@C6r
httpConnection.setRequestProperty("User-Agent","NetFox"); `\5u/i'Ca!
+*ZF52hy|
6-h(305A
int responseCode=httpConnection.getResponseCode(); u:s[6T0
if(responseCode>=400) 7xy[;
{ 1;N5@0%p
processErrorCode(responseCode); E [b6k&A
return -2; //-2 represent access is error 1|/]bffg!c
} iF'qaqHWY4
tw%z!u[a
tg'2v/
String sHeader; S{F'k;x/5
U%E364;F
)xj!7:n)
for(int i=1;;i++) ]pP:
{ )r.4`5Rc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QO(P_az3mg
//Utility.log(in.readLine()); 5Cjh%rj(jl
sHeader=httpConnection.getHeaderFieldKey(i); >7I"_#x1:
if(sHeader!=null) k86j& .m_
{ 55#s/`gd)^
if(sHeader.equals("Content-Length")) B~t[Gy
{ ?0k4l8R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lzup! `g
break; TuX9:Q
} Rt2<F-gY
} k9vzxZ%s:
else m6^n8%
break; !,zRg5Wp4
} TW5Pt{X=f
} \zGmZZ
catch(IOException e){e.printStackTrace ();} f?|cQ[#t!\
catch(Exception e){e.printStackTrace ();} q}0xQjpo
@<,YUp,%S
b'$fr6"O1
Utility.log(nFileLength); q7ubRak
oVYW'~OID
)=@SA`J
return nFileLength; =9y&j-F
} 6A,-?W'\
7\nR'MOZ
Tq*K =^
//保存下载信息（文件指针位置） t2 0Es
private void write_nPos() 40)Ti
{ 4fa2_
try{ Qy_! +q
output = new DataOutputStream(new FileOutputStream(tmpFile)); S<bsrS*$
output.writeInt(nStartPos.length); ;j^C35
for(int i=0;i<nStartPos.length;i++) vm Y*K
{ 1NQstmd{
// output.writeLong(nPos); JuTIP6 /G
output.writeLong(fileSplitterFetch.nStartPos); Hm*?<o9mxC
output.writeLong(fileSplitterFetch.nEndPos); O[O[E}8#
} i]M:ntB"
output.close(); * j]"I=D
} X[r\ Qa
catch(IOException e){e.printStackTrace ();} '|^<|S_+K
catch(Exception e){e.printStackTrace ();} i_M0P12
} ~rICPR
[+4/M3J%
$:D-dUr1
//读取保存的下载信息（文件指针位置） rI.CCPY~s
private void read_nPos() GB\1'
{ h#Q Sx@U6
try{ BA(PWX`H
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lZf=#
int nCount = input.readInt(); =LHz[dSL
nStartPos = new long[nCount]; _,{R3k
nEndPos = new long[nCount]; k2Y *
for(int i=0;i<nStartPos.length;i++) S"skKh4w
{ w9Z,3J6r
nStartPos = input.readLong(); FvVR \a
nEndPos = input.readLong(); N~t4qlC/
} %MH!L2|
input.close(); ^a{cK
} CE;J`;
catch(IOException e){e.printStackTrace ();} CP"
catch(Exception e){e.printStackTrace ();} vS'l@`Eg]
} t`oH7)nut
j'M=+
(>a8h~Na
private void processErrorCode(int nErrorCode) ywj'S7~A
{ \mGok<b4
System.err.println("Error Code : " + nErrorCode); 5,Hj$v7fe
} >IFqwh7b
3:~ *cU
%=EN 3>,
//停止文件下载 m(o^9R_=^9
public void siteStop() "nQ&~KQ
{ lz>>{
bStop = true; )E>nr Z
for(int i=0;i<nStartPos.length;i++) <yxy ;o
fileSplitterFetch.splitterStop(); K 0Gm ?(
6Ud6F t6
{$fd?| 9h
} l`k""f69W
} (N 0kTi]b
//负责部分文件的抓取 gof'NT\c
**FileSplitterFetch.java 7x5wT ?2W
*/ JNk6:j&Pf
package NetFox; yHNx,ra
)g ; !IL
7wB*@a-
import java.io.*; H{CiN
import java.net.*; L-z9n@=8\
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.bloaeu-
public class FileSplitterFetch extends Thread { :Cdqj0O3u
pb5q2|u`h
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String sURL; //File URL "f|xIK`c
long nStartPos; //File Snippet Start Position wpI_yp
long nEndPos; //File Snippet End Position vtu!* 7m
int nThreadID; //Thread's ID Y6w7sr_R
boolean bDownOver = false; //Downing is over Wv7hY"
boolean bStop = false; //Stop identical }{y(&Oy3Y
FileAccessI fileAccessI = null; //File Access interface 7*I:cga
2.PZtl
OLs<]0H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K);)$8K
{ =%Z5"];
this.sURL = sURL; A\:u5(
this.nStartPos = nStart; c%x9.s<+1
this.nEndPos = nEnd; 1];OGJuJ2
nThreadID = id; .4O~a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "HwSW4a]
} qayM0i>>
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o>i@2_r\&H
public void run() TnXx;v
{ a4E{7c
while(nStartPos < nEndPos && !bStop) Xt9vTCox
{ 7,7-E&d
Or3GrZ!H
tQWjNP~
try{ -|g9__|@
URL url = new URL(sURL); )kk10AZV-E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Bj*\)lG<
httpConnection.setRequestProperty("User-Agent","NetFox"); qac8zt#2 C
String sProperty = "bytes="+nStartPos+"-"; {v>8Kp7_R
httpConnection.setRequestProperty("RANGE",sProperty); GJTakhj3
Utility.log(sProperty); P1qQ)-J
aGbHDo
J|=0 :G
InputStream input = httpConnection.getInputStream(); 5`\"UC7?%
//logResponseHead(httpConnection); L"Dos +
dKJ-{LV
M'|?*aNK
byte[] b = new byte[1024]; !=bGU=^
int nRead; 4H*M^?h\#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h-+vNhH
{ V:<Z
nStartPos += fileAccessI.write(b,0,nRead); >QSlH]M
//if(nThreadID == 1) 9!?Ywc>0#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7xh91EU:4
} iBh.&K{j
AkAQ%)6qV
Iq@&?,W
Utility.log("Thread " + nThreadID + " is over!"); KD^n7+w%
bDownOver = true; @fh:lsw
//nPos = fileAccessI.write (b,0,nRead); LMHiiOs,
} w`I+4&/h
catch(Exception e){e.printStackTrace ();} A{%LL r:
} a&Z;$
} Bg.
Oj8xc!d'
Dp-j(F
//打印回应的头信息 q#PMQR"C
public void logResponseHead(HttpURLConnection con) u9u'!hAGH
{ V>(>wSR
for(int i=1;;i++) nq qqP
{ k7kPeq
String header=con.getHeaderFieldKey(i); }uiD8b{I
if(header!=null) au#/Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wK!7mZ
Utility.log(header+" : "+con.getHeaderField(header)); }fZ~HqS2w
else P!u0_6
break; g&r3;
} 5Zuk`%O
} ^GnR1.ux
IC:>60A,]
+FH@|~^O
public void splitterStop() V='A;gs
{ #`@5`;U>#
bStop = true; ov\+&=IRG
} oq9gFJG(
&G)/i*
nSpOTQ
} V;d<S@$
rEwd76?
ZxAk
/* _[h!r;DsG
**FileAccess.java t~%(Zu>S
*//文件访问(定位，写) q}gM2Ia'vY
package NetFox; ${{[g16X
import java.io.*; WI1DL&*B@<
snP]&l+
N{H#j6QW
public class FileAccessI implements Serializable{ q{l %k
2$Umqt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *X uIA-9
RandomAccessFile oSavedFile; 3,0b<vfSv
long nPos; MDCwgNPiQW
>Z>sR0s7
^B$cfs@*
public FileAccessI() throws IOException M^{=&
{ n(#[[k9&Ic
this("",0); 49=L9:
} Nz>xilU'
|]eWO#vs
h{: ]'/@~
public FileAccessI(String sName,long nPos) throws IOException tuJ{IF
{ kTA4!654
oSavedFile = new RandomAccessFile(sName,"rw"); %wco)2
this.nPos = nPos; \$!D^%~;
oSavedFile.seek(nPos); umN4|X
} xoQ(GrBY
7LsVlT[
U#`2~Qv/1
public synchronized int write(byte[] b,int nStart,int nLen) D*'sOB(
{ B\tm
int n = -1; tA^CuJR
try{ l[^0Ik-G
oSavedFile.write(b,nStart,nLen); Q_`EKz;N{
n = nLen; :}CcWfbT
} T%aM~dp
catch(IOException e) _k#!^AJ}x
{ K"zRj L+
e.printStackTrace (); gF:|j(
} qq"0X! w
=1\mLI}@
0|ekwTx.
return n; fo~>y
} '4}8WYKQ
+1^L35\@
y?Pw6;e.
} {a]u
4'"WD0
=R)w=ce
/* 8?ip,Q\
**SiteInfoBean.java 9\uBX.]x
*/ [#%@,C
package NetFox; Sa@T#%oU
I~4!8W-Y
?kS#g
public class SiteInfoBean { `A<2wd;
K{:[0oIHc
LTuT"}dT[
private String sSiteURL; //Site's URL %CQv&d2
private String sFilePath; //Saved File's Path r}}2Kl
private String sFileName; //Saved File's Name !6hV|2aJy
private int nSplitter; //Count of Splited Downloading File sl:1P^b
K^P&3H*(/n
:i|Bz6Ht4
public SiteInfoBean() v8zOY#?
{//nSplitter的缺省值为5 LtPaTe
//default value of nSplitter is 5 Hc-up.?v'v
this("","","",5); q2/kegAT
} }*S`1IWMj
c]"w0a-`^@
j/@<=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tJ .Ln
{ ;*hVAxs1
sSiteURL= sURL; jhJ<JDJ?`
sFilePath = sPath; '(-H#D.oy'
sFileName = sName; ez~u A4
this.nSplitter = nSpiltter; IaKJ W?
#Z,@yJ2wl
dptfIBYc+
} !x!1H5"
bXA%|7*
K"ly\$F
public String getSSiteURL() @>&b&uj7T
{ x~F YG
return sSiteURL; 7a=ul:
} O:ACp<@
">MsV/
G cB<i
public void setSSiteURL(String value) Zu4au<
{ KGc!#C
sSiteURL = value; cj[x%eK>
} smn~p/u
MI-S}Qoe
@bChJl4
public String getSFilePath() v+o6ZNX
{ '}:(y$9.`
return sFilePath; ].sD#~L_
} C-g,uARX(r
/1_O5'5+v
wPq9`9 #
public void setSFilePath(String value) .hUlI3z9
{ ,3!TyQ\m'
sFilePath = value; %:j`%F;R
} 9W,%[
j& ykce
f$vU$>+[
public String getSFileName() rjj_]1?K
{ ;-_ZWk]
return sFileName; %gWQ}QF
} MNp4=R
AMASh*
KzQFG)q,
public void setSFileName(String value) y:_>R=sw
{ d c/^
sFileName = value; RJKi98xwJ
} rITA-W O
1K(mdL{m5
*!E~4z=
public int getNSplitter() fs-LaV 0
{ tx)$4v
return nSplitter; R0mkEM
} j<`3xd'
`VvQems
8(\J~I[^
public void setNSplitter(int nCount) 7SNdC8GZ~
{ lBm`W]3T
nSplitter = nCount; 3,2$Ny3N
} w'XN<RWA
} j\zlp
Z9|A"[b
s0:M'wA
/* 9JX@ck
**Utility.java 7GS4gSd3
*/ 1hSV/%v_
package NetFox; Z>3m-:-e
1.PN_9%
?\(qA+iP0
public class Utility { m*YfbOhs#
,k*%=TF7N
FBvh7D.hV
public Utility() \S1W,H|
{ ZJm$7T)V
$M/1pZ
8nL9#b
} SlHDBr!.z
t0r0{:
//线程睡眠 +@yU `
public static void sleep(int nSecond) g-B{K "z
{ g^x=y
try{ ^2{6W6=
Thread.sleep(nSecond); (h@!_qi9:
} /y|ZAN
catch(Exception e) 2`j{n\/
{ A{M7
e.printStackTrace (); N%ccy?B
} d R=0K
} qL`yaU
ZI1*Cb
//日志 }fv7WhQ
public static void log(String sMsg) !uO@4]:Y
{ ~j(vGO3JB
System.err.println(sMsg); 87W!R<G
} u;!h
bsr]Z&9rrk
:I7mMy*
public static void log(int sMsg) `&h-+
{ R*0mCz^+h
System.err.println(sMsg); ,zr,>^v
} .tppCy
} 0rz1b6F5,
*po o.Zz
Km!ACA&s6
/* iSR"$H{
**TestMethod.java BFhEDkk
*/ nB5\ocJ
package NetFox; \13Q>iAu
*3!r &iY
w!v^6[!
public class TestMethod { NZa 7[}H
`(`-S md
68(^*
public TestMethod() cruBJZr*
{ ///xx/weblogic60b2_win.exe =:zPT;K
try{ x X[WX#'f
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HFTeG4R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b/Ma,}
SiteFileFetch fileFetch = new SiteFileFetch(bean); zwRF-{s
fileFetch.start(); LI25VDZ|iP
} &BNlMF
catch(Exception e){e.printStackTrace ();} sD2,!/'
v\MQ?VC
NZ&ZK@h}.
} ao=e{R)
mqHH1}
`LLmdm 6i
public static void main(String[] args) /5z,G r
{ " DLIx}
new TestMethod(); 5c(g7N
} "C&>$h_%
} LwxJ:Kz.
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