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)); EG\L]fmD
} s>;"bzzq
for(int i=0;i<nEndPos.length-1;i++) ~"S5KroN
{ )[hs#nKTh
nEndPos = nStartPos[i+1]; _A]jiPq
} *4~7p4[
nEndPos[nEndPos.length-1] = nFileLength; Y#lAG@$
} s-*N_Dv
} `_vPElQXZ#
<@`K^g;W
q"Bd-?9
//启动子线程 d '2JMdbc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hak#Iz0[C
for(int i=0;i<nStartPos.length;i++) K/(LF}
{ 6iQqOAG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QqL?? p-S>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2^s&#@n3t
nStartPos,nEndPos,i); (a!E3y5,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QPVr:+\B{
fileSplitterFetch.start(); [ 2@Lc3<
} IF>v -Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H?opG<R=ek
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Uj 3{c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I-.?qcy~
nEndPos = " + nFileLength); [9?]|4
// fileSplitterFetch[nPos.length-1].start(); Q3lVx5G>4
Bptt"
UDpI @
//等待子线程结束 9F,XjPK=
//int count = 0; 3sBWtz
//是否结束while循环 1slt[&4N
boolean breakWhile = false; \^F6)COy
|RpZr!3V
^R\5'9K!
while(!bStop) M]\"]H?
{ ,[m4+6G5
write_nPos(); 5NSXSR9c
Utility.sleep(500); j@JY-^~K5
breakWhile = true; TuMZHB7h;
p*P0<01Z
W6B o\UK
for(int i=0;i<nStartPos.length;i++) *|+ ~V/#
{ bVRxGn @l
if(!fileSplitterFetch.bDownOver) _}Gs9sHr0K
{ :+DAzjwO<
breakWhile = false; n O}x,sG2'
break; b=Sl`&A
} ;c~DBJg'|
} '9wD+'c=A
if(breakWhile) G`!;RX
break; _ )^n[_E
DA4!-\bt@
X>jwjRK $
//count++; S67T:ARS
//if(count>4) QQjMC'
// siteStop(); m4P=,=%
} D+_PyK~jc
dR/UXzrc
**YNR:#Y
System.err.println("文件下载结束！"); ;lWy?53=@
} $j}sxxTT
catch(Exception e){e.printStackTrace ();} Tf[-8H<
} >Q\H1|?
Mz{ Rh+gS
u= +
//获得文件长度 "/XS3sv"s
public long getFileSize() XKU=VOY
{ 7#|NQ=yd
int nFileLength = -1; kAk,:a;P
try{ .y[K =p3
URL url = new URL(siteInfoBean.getSSiteURL()); Mw5!9@Fc7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7iJk0L$]x
httpConnection.setRequestProperty("User-Agent","NetFox"); :~)Q]G1Nj
=yNHJHRA#
;09J;sf
int responseCode=httpConnection.getResponseCode(); /s*>V@Q
if(responseCode>=400) @x J^JcE
{ +`Bn]e8O
processErrorCode(responseCode); <,hBoHZSL
return -2; //-2 represent access is error u#UeJuO
} gS|xicq!
hA\8&pI;
rqh,BkQ0t
String sHeader; o5$K^2^g
a!^wc,
S+>]8ZY
for(int i=1;;i++) ]D-48o0
{ E;d 5$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yaR;
//Utility.log(in.readLine()); y?@Y\ b
sHeader=httpConnection.getHeaderFieldKey(i); Cw|SY
if(sHeader!=null) *nW9)T
{ v#+w<gRq
if(sHeader.equals("Content-Length")) EH "g`r
{ ,]{NZ9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W=\dsdnu*
break; C;) xjZiR
} 4vQHr!$Ep
} 3ElpS^2W
else U?lu@5 ^Z
break; hw'2q9J|
} l9ihW^
} bg*{1^
catch(IOException e){e.printStackTrace ();} ge oN4
catch(Exception e){e.printStackTrace ();} uY~A0I5Z
'> Q$5R1
u.=;A#
Utility.log(nFileLength); =5M>\vt]
U[D<%7f
ggTjd"|)
return nFileLength; ^aW[~ c
} ,6S8s
5l}h8So4
dR+$7N$
//保存下载信息（文件指针位置） ksaC[G;}:
private void write_nPos() RGLA}|
{ DS2$w9!
try{ 6v#G'M#r
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~QcKW<bz
output.writeInt(nStartPos.length); .Cus t
for(int i=0;i<nStartPos.length;i++) s-V$N
{ ~\G3l,4
// output.writeLong(nPos); vrv*k
output.writeLong(fileSplitterFetch.nStartPos); fdG.=7`
output.writeLong(fileSplitterFetch.nEndPos); B^?XE(.
} wcf_5T
output.close(); vNSf:5H$
} bVHi3=0{
catch(IOException e){e.printStackTrace ();} wS0bk<(
catch(Exception e){e.printStackTrace ();} :a@z53X@M
} 6w;|-/:`
|u;PU`^-z
2QRn c"
//读取保存的下载信息（文件指针位置） iGMONJRO
private void read_nPos() W@dY:N}
{ oLMi vy4
try{ p&mtKLv
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?\M6P?tpo&
int nCount = input.readInt(); p'k+0=
nStartPos = new long[nCount]; QJM!Wx+
nEndPos = new long[nCount]; S\;.nAR
for(int i=0;i<nStartPos.length;i++) E57{*C
{ veg!mY2&
nStartPos = input.readLong(); 6ya87H'e@
nEndPos = input.readLong(); (v:ek_
} E}9ldM=]s
input.close(); H<}eoU.
} gdE`UZ\
catch(IOException e){e.printStackTrace ();} 'a^tL[rLP1
catch(Exception e){e.printStackTrace ();} yKEFne8^
} DF|s,J`98
!gfhEzY
(<ZkmIXN
private void processErrorCode(int nErrorCode) `lezJ(Xm
{ X6GkJ R
System.err.println("Error Code : " + nErrorCode); xevP2pYG:
} E0^%|Mh]b
l)*,18n
%`1CE\f
//停止文件下载 >-5Gt
public void siteStop() I''R\Bp
{ `{lAhZ5
bStop = true; {a8^6dm*E
for(int i=0;i<nStartPos.length;i++) UW[{d/.wC
fileSplitterFetch.splitterStop(); i6#]$B
JOx,19r
(2bZ]
} @@3,+7%1
} a<wQzgxG
//负责部分文件的抓取 /dJ)TW(Ir
**FileSplitterFetch.java @PoFxv
*/ q6JW@GT
package NetFox; h<'5q&y
X0Z-1bs
14n="-9
import java.io.*; ?t0zsq
import java.net.*; 1m<?Q&|m$
}#HTO:r
lAn+gDP
public class FileSplitterFetch extends Thread { Z\=04[
=PFR{=F
SAG`^t
String sURL; //File URL yvooM'R
long nStartPos; //File Snippet Start Position 2iPmCG
long nEndPos; //File Snippet End Position seuN,jpt
int nThreadID; //Thread's ID e4=FU&RpNH
boolean bDownOver = false; //Downing is over &xBK\
boolean bStop = false; //Stop identical '`]n_$f'
FileAccessI fileAccessI = null; //File Access interface $TA6S+
`!omzE*bk5
RHx+HBZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J(EaE2
{ VqClM
this.sURL = sURL; JU'WiR bcb
this.nStartPos = nStart; FS`vK`'
this.nEndPos = nEnd; uqa4&2(I=j
nThreadID = id; OS"{"P
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xv$)u<Ve
} EO].qN-8
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T1(j l)
public void run() C,{F0-D
{ 7bonOt Y
while(nStartPos < nEndPos && !bStop) lHcZi
{ -OrY{^F
,l$NJt
i!Dh&XT
try{ (}{_]X|e
URL url = new URL(sURL); _oJ2]f6KX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #ox9&
httpConnection.setRequestProperty("User-Agent","NetFox"); y8w0eq94
String sProperty = "bytes="+nStartPos+"-"; *|LbbRu
httpConnection.setRequestProperty("RANGE",sProperty); kRN|TDx(
Utility.log(sProperty); iY ^{wi~?
selP=Q!
Vl{~@G,@
InputStream input = httpConnection.getInputStream(); aFRTNu/r
//logResponseHead(httpConnection); K,eqD<
3:[!t%Yb
*.m{jgi1X
byte[] b = new byte[1024]; _{6,.TN
int nRead; x?,~TC4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1mJbQ#5
{ Hva2j<h
nStartPos += fileAccessI.write(b,0,nRead); X0y?<G1(a
//if(nThreadID == 1) ^oQekga\l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F8{ldzh
} {q&@nm40
klgv{_b
8To7c
Utility.log("Thread " + nThreadID + " is over!"); |Du,UY/
bDownOver = true; (jM<T;4
//nPos = fileAccessI.write (b,0,nRead); 3<c*v/L{C\
} 1P_Fe[8
catch(Exception e){e.printStackTrace ();} 8#+`9GI
} paW'R+Rck
} .aNO( /kO
IWAj Mwo
DVObrL)znL
//打印回应的头信息 0jBKCu
public void logResponseHead(HttpURLConnection con) 9[z'/U.Bn
{ A)8rk_92Q
for(int i=1;;i++) C@%iQ]=
{ 0/ut:RV0
String header=con.getHeaderFieldKey(i); " Wp
if(header!=null) +x(YG(5\w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k_]$myq
Utility.log(header+" : "+con.getHeaderField(header)); z{%oJ_
else KzV.+f
break; ucw`;<d8
} vx'l>@]k
} j*XjY[
I$n+DwKcN
$( S*GF$S
public void splitterStop() 9*' &5F=
{ W+KF2(lB
bStop = true; O47PkP8
} Q\H_t)-
]*0(-@
UanEzx%
} q$F)!&
fTBVvY4(
*\D}eBd|
/* |7y6 pz
**FileAccess.java <P-$RX
*//文件访问(定位，写) E-^2"j>o
package NetFox; f_rp<R>Uu
import java.io.*; a~,Kz\Tt
hqL+_|DW
^CUSlnB\(
public class FileAccessI implements Serializable{ `g--QR
)T9~8p.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [P{a_(
RandomAccessFile oSavedFile; s'TY[
long nPos; [,rn3CA
h(nj,X+
nWk e#{[
public FileAccessI() throws IOException ]w!0u2K<Q\
{ LX$8~dp
this("",0); U9 bWU'
} 9p4y>3
D*QYKW=)
)&:L'N
public FileAccessI(String sName,long nPos) throws IOException gGEIK0\{
{ /D'M24
oSavedFile = new RandomAccessFile(sName,"rw"); KzNm^^#/$A
this.nPos = nPos; Z5$fE7ba+
oSavedFile.seek(nPos); ~@D/A/|
} s9i|mVtm8
U7h(-dV
P\AqpQv
public synchronized int write(byte[] b,int nStart,int nLen) 6WeM rWx
{ 'C^;OjAg
int n = -1; {~_Y _-
try{ m'bi\1Q
oSavedFile.write(b,nStart,nLen); cI:-Z{M7z
n = nLen; LTXz$Z]
} /P:EWUf'
catch(IOException e) [9AM\n>g
{ k"0;D-lTZ>
e.printStackTrace (); wt?o 7R2
} lL0M^Nv
g*J@[y;
~8{sA5y
return n; Xb,T{.3@
} Ac`;st%l.
A[)C:q,
"%@v++4y
} -ihiG_f
v+6e;xl8
J+ts
/* y' [LNp V
**SiteInfoBean.java .Y\EE;8%
*/ I 8zG~L%"
package NetFox; hqDqt"dKz
g`[$XiR
o\!qcoE2W
public class SiteInfoBean { rt}^4IqL
/pykW_`/-
%\6Q .V#s
private String sSiteURL; //Site's URL Ej"u1F14J
private String sFilePath; //Saved File's Path h/m6)m.D
private String sFileName; //Saved File's Name !%[S49s
private int nSplitter; //Count of Splited Downloading File #|f~s
izuF !9
8@eOTzm
public SiteInfoBean() O|'1B>X
{//nSplitter的缺省值为5 eV2mMSY
//default value of nSplitter is 5 !20XsO
this("","","",5); efOjTA%
} G5Ykbw#
/XbW<dfl
z7T0u.4Ss
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ea9oakF
{ ZA820A>2!
sSiteURL= sURL; '*T]fND4
sFilePath = sPath; ~ap2m
sFileName = sName; fY W|p<Q0
this.nSplitter = nSpiltter; :Li/=>R^
$NG++N
Ed-M7#wY
} Or+p%K}-7
rRb+_]Lg
5kMWW*Xtf
public String getSSiteURL() caq} &A]C
{ WNy3@+@GZ
return sSiteURL; m9":{JI.w
} 2`bdrRD0
L%h/OD
C+N k"l9
public void setSSiteURL(String value) .*5Z"Q['G
{ Es4qPB`g.
sSiteURL = value; K5 KyG
} 55DE\<r
.\:J~(
j*R,m1e8
public String getSFilePath() Z-X?JA\&
{ iK;opA"
return sFilePath; @cD uhK"U}
} v~)LO2y
QlZ@ To
anN#5jt
public void setSFilePath(String value) B80aw>M
{ =Lp7{09u
sFilePath = value; =o7}]k7
} +OHGn;C
l*=aMjd?
TnH\O$
public String getSFileName() ,xsH|xW
{ $)Bg JDr
return sFileName; *_-'/i
} m`A% p
rZ03x\2
xL "!~dN
public void setSFileName(String value) 1DJekiWf
{ zj{s}*
sFileName = value; b/("Y.r=
} nv/[I,nw
ml!5:r>
$lwz-^1t.
public int getNSplitter() oF&l-DHp
{ ^QXbJJ
return nSplitter; 42C<1@>zO
} Y3U9:VB
hpbf&S4
a[!%Ld
public void setNSplitter(int nCount) o>]`ac0b}Y
{ 0y#Ih {L
nSplitter = nCount; ?&+9WJ<M
} p*3; hGp6
} ]+Ixi o
KLWDo%%u
(R}ii}&
/* 6;b9swmh
**Utility.java wIvo"|%
*/ 2\<.0
package NetFox; z?]G3$i(
2[yBD-":
[U{UW4
public class Utility { 5g5'@vMN
Q /x8 #X
@* ust>7
public Utility() {p<Zbm.
{ 8(U{2B8>\%
a:STQk V
}?@5W,
} 4Ft1@
,\)a_@@k
//线程睡眠 Rd*[%)
public static void sleep(int nSecond) W&Y"K)`
{ u,.3
try{ [#^#+ |{\
Thread.sleep(nSecond); 3(E $I5
} g=@_Z"
catch(Exception e) |,C#:"z;
{ v6(E3)J7
e.printStackTrace (); a6xj\w
} }ut]\]b
} )(M7lq.e7
8T[ 6J{|C
//日志 <=K qcHb
public static void log(String sMsg) z9/G4^qF
{ g2cVZ!GIj
System.err.println(sMsg); JAc_kl{4O
} S^I,Iz+`S'
(?)7)5H
<!d"E@%v@
public static void log(int sMsg) ,~PYt*X4
{ >TL^>D
System.err.println(sMsg); zt24qTKL
} XKOUQc4!R
} 1Nn@L2b 2
+xv!$gJEj
Z4TL6]^R
/* c,EBF\r8*
**TestMethod.java Rg&-0b
*/ x+5k <Xi}
package NetFox; $"JpFT
imB#Eo4eY
iOw3MfO
public class TestMethod { M5L{*>4|6
K]oM8H1
|iYg >
public TestMethod() rt-\g1x
{ ///xx/weblogic60b2_win.exe Ji'(`9F&a
try{ -XK0KYhgW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AIl4]F5I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Nt`b;X&
SiteFileFetch fileFetch = new SiteFileFetch(bean); o?Nu:&yE
fileFetch.start(); _cH@I?B
} `|O yRU"EK
catch(Exception e){e.printStackTrace ();} @~ Dh'w2q
Et2JxbD
}ucIH@U{
} nt1CTWKM8^
n`Z"rwKmNw
&[R8Q|1j
public static void main(String[] args) 1MsWnSvzf
{ V~MiO.B
new TestMethod(); !cW[G/W8
} q0mOG^
} ~,6b_W p/
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