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)); b`$yqi<[
} lK0s=4c{
for(int i=0;i<nEndPos.length-1;i++) d:A}CBTSY
{ e|yX QTlvL
nEndPos = nStartPos[i+1]; J0=7'@(p
} |~z3U>
nEndPos[nEndPos.length-1] = nFileLength; Odm#wL~E
} xdPcsox~
} YQ; cJ$
)T9;6R$b
Rq) 0i}F
//启动子线程 d^PD#&"g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :4|M jn
for(int i=0;i<nStartPos.length;i++) 2+z1h^)W
{ )B6# A0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uS~#4;R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4CLsY n?
nStartPos,nEndPos,i); UH[<&v
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uKv&7p@|_)
fileSplitterFetch.start(); hi!`9k
} qP7G[%=v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WJfES2N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2UiR~P]%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GD!- qH
nEndPos = " + nFileLength); 9CB\n
// fileSplitterFetch[nPos.length-1].start(); ]bm=LA
"f4<B-9<$
5y]io Jc9-
//等待子线程结束 >-M ]:=L
//int count = 0; #b'N}2'p#V
//是否结束while循环 ^5>s7SGB"
boolean breakWhile = false; $_sYfU9
C}q>YRubZ
.jA\f:u#
while(!bStop) ld.7`)
{ joqWh!kv7U
write_nPos(); pE2QnNr'
Utility.sleep(500); Ea-bC:>
breakWhile = true; 4jQ'+ 2it
b^x07lO
/t*YDWLg
for(int i=0;i<nStartPos.length;i++) WfZF~$li`
{ C ZJV_0
if(!fileSplitterFetch.bDownOver) Vo\H<_=G
{ >)NQH9'1
breakWhile = false; eX"''PA
break; \6o\+OQk
} 3+ =I;nj
} YGp)Oy}:
if(breakWhile) /;Yy@oc
break; nU2V]-qY
'f+NW&
)s)_XL
//count++; NgVR,G|1
//if(count>4) R(G\wqHUT3
// siteStop(); v8m`jxII64
} x0A7O
/_)l|<k+V
<*<U!J-i
System.err.println("文件下载结束！"); z}+i=cAN
} RP! X8~8
catch(Exception e){e.printStackTrace ();} )u*^@Wo
} GKZN}bOm\
*)'Vvu<
[k$efwJ
//获得文件长度 =xL)$DTg)
public long getFileSize() _7"5wB?|+
{ n*<v]1
int nFileLength = -1; .po>qb6
try{ o_f-GO
URL url = new URL(siteInfoBean.getSSiteURL()); e\F}q)_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \K7t'20
httpConnection.setRequestProperty("User-Agent","NetFox"); F}36IM9/:
9pLg+6O
~jN'J+_$
int responseCode=httpConnection.getResponseCode(); ~}'F887f
if(responseCode>=400) SJk>Jt=
{ or2|O#=
processErrorCode(responseCode); )K;]y-Us[
return -2; //-2 represent access is error kccWoU,
} Y/fJQ6DY
k_ Y~;P@
Dz;HAyPj
String sHeader; MzkkcQLK
bcH_V|5}
BMFF=
for(int i=1;;i++) Q`ME@vz
{ S_b/DO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xj@+{uvQB
//Utility.log(in.readLine()); ^A9M;q
sHeader=httpConnection.getHeaderFieldKey(i); p=Y>i 'CG
if(sHeader!=null) .tnkT;T
{ ;a r><w
if(sHeader.equals("Content-Length")) y9L14
{ %w ) +V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d ~`V7B2Y
break; g`0moXz
} [syj#
} 3^,QIG
else G$bJ+
break; !yJICjXj
} ,SUT~oETP
} )d`mvZBn1
catch(IOException e){e.printStackTrace ();} I:l01W;
catch(Exception e){e.printStackTrace ();} +v7) 1y
Kct@87z
28I^$> [
Utility.log(nFileLength); KpHw-6"
BPv>$ m+.
@S^ASDuQU7
return nFileLength; fjG&`m#"
} wTc)S6%7
`yO'[2
HrM$NRhu
//保存下载信息（文件指针位置） q7\Ovjs0
private void write_nPos() F<|t\KOW
{ swcd&~9r
try{ >IfV\w32
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZDt?j
output.writeInt(nStartPos.length); k N7Bd}
for(int i=0;i<nStartPos.length;i++) ztll}
{ 5B4Ssrs5W~
// output.writeLong(nPos); %,P>%'0
output.writeLong(fileSplitterFetch.nStartPos); *ZrSiIPP
output.writeLong(fileSplitterFetch.nEndPos); 0~Gle:
} WFTvOFj
output.close(); ravyiOL
} aZS7sV28
catch(IOException e){e.printStackTrace ();} A8r^)QJP{
catch(Exception e){e.printStackTrace ();} /F)H\*
} K> g[k_
}G VX>p
GVGlVAo|@
//读取保存的下载信息（文件指针位置） V3Z]DA
private void read_nPos() x;s0j"`Jb
{ p@ NaD=9
try{ pzZk\-0R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #5} wuj%5
int nCount = input.readInt(); YJV%a
nStartPos = new long[nCount]; .a'f|c6
nEndPos = new long[nCount]; 4rg2y]
for(int i=0;i<nStartPos.length;i++) Xf[kI
{ yx38g ca
nStartPos = input.readLong(); zeb=8Dg :
nEndPos = input.readLong(); \M<3}t
} 4T6 {Y
input.close(); I:98$r$
} 64>krmVIe
catch(IOException e){e.printStackTrace ();} (V:E2WR
catch(Exception e){e.printStackTrace ();} V!_71x\-Q
} zP\7S}p7%
R%Y`=pK>}
W~1~k{A
private void processErrorCode(int nErrorCode) avQJPB)}Sb
{ "R>FqX6FB
System.err.println("Error Code : " + nErrorCode); CusF/>
} j=RRfFg)
o\b-_E5"?
{i0SS
//停止文件下载 ]:M0Kj&h
public void siteStop() O^Q7b7}y
{ 8.AR.o
bStop = true; kRCQv-*
for(int i=0;i<nStartPos.length;i++) /AY4M;}p
fileSplitterFetch.splitterStop(); F,BOgWwP
'xY@x-o
"\C$
} Yb3mP!3q8Z
} GzXUU@p
//负责部分文件的抓取 N["W Ir
**FileSplitterFetch.java nAIo{ F
*/ *g}Yw
package NetFox; YHkcWz
GPz(j'jU
JF&$t}
import java.io.*; K.<.cJE
import java.net.*; i9<pqQ
Q_-_^J
JxE53ev
public class FileSplitterFetch extends Thread { y$FW$Ka
Z;Ez"t&U
[qUN4x5b
String sURL; //File URL }D411228
long nStartPos; //File Snippet Start Position jp8@vdRg
long nEndPos; //File Snippet End Position . o7m!
int nThreadID; //Thread's ID `nM/l@
boolean bDownOver = false; //Downing is over I-y#Ks1p+
boolean bStop = false; //Stop identical KqBk~-G
FileAccessI fileAccessI = null; //File Access interface McH>"`
9EDfd NN
3$.deYa$R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0R{dNyh{
{ X[ q+619
this.sURL = sURL; 3vhnwDcK
this.nStartPos = nStart; {"oxJ`z4
this.nEndPos = nEnd; "Ve.cP,7(
nThreadID = id; eAv4FA4g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wO ?+Nh
} U*Ge<(v$
m8'C_U^89
L^2FQti>
public void run() dm0QcW4
{ wW>zgTG
while(nStartPos < nEndPos && !bStop) xh7cVE[UM
{ f` =CpO*
_XJ2fA )
(" LQll9
try{ kt`nbm|aw
URL url = new URL(sURL); ];.pK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7+X:LA~U
httpConnection.setRequestProperty("User-Agent","NetFox"); "k]CW\H6z
String sProperty = "bytes="+nStartPos+"-"; G9g1hie@%
httpConnection.setRequestProperty("RANGE",sProperty); O"Ku1t!
Utility.log(sProperty); O+g3X5f+
* #jsgj[
mPI8_5V8]
InputStream input = httpConnection.getInputStream(); 0/S_e)U
//logResponseHead(httpConnection); }ci#>
3"o"fl
'smWLz}
byte[] b = new byte[1024]; 8} =JKR^cK
int nRead; ono4U.C9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) PH"n{lW.T
{ :Y9NLbv
nStartPos += fileAccessI.write(b,0,nRead); f$NMM >z
//if(nThreadID == 1) NR;1z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ml\4xp,
} T,| 1g6
X[f=h=|
r.4LU
Utility.log("Thread " + nThreadID + " is over!"); !r#?C9Sq
bDownOver = true; V&-~x^JK
//nPos = fileAccessI.write (b,0,nRead); M\yT).>z
} Neg,qOt
catch(Exception e){e.printStackTrace ();} oc8:r
} =Umw$+fJr
} sB;@>NY
8_T6_jL<
!\&;h
//打印回应的头信息 sC9&Dgkk
public void logResponseHead(HttpURLConnection con) TMYd47
{ A&nU]R8S
for(int i=1;;i++) PO6&bIr
{ m0v:\?S:
String header=con.getHeaderFieldKey(i); &f&z_WU
if(header!=null) J_s>N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LX^u_Iu
Utility.log(header+" : "+con.getHeaderField(header)); u_ABt?'
else H54R8O$
break; &|/| ''A)
} 5 ~TdD6}
} [Q=dCX9%
@}u9Rn*d;
_YF%V;X
public void splitterStop() X7s `U5'l
{ (V4 ~`i4V
bStop = true; ]c! ;L5
} .A6(D$O k
K)J(./
7b<yVP;{
} ULQMG'P^D
hWX% 66
\Gc+WpS(
/* Z)jw|T'X
**FileAccess.java "HPB!)C8(
*//文件访问(定位，写) i&VsW7
package NetFox; _cXqAo[V
import java.io.*; qh`t-
XLH0 ;+CL{
_-EyT
public class FileAccessI implements Serializable{ 3YVi" k?2
-|E!e.^7:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;VWAf;U;B
RandomAccessFile oSavedFile; $sEy%-
long nPos; 'Fmvu
o<N nV
EVoEszR
public FileAccessI() throws IOException /iX+R@
{ 0{=`on;
this("",0); ,T2G~^0
} -;'1^
7}X[ 4("bB
3D2E?$dX
public FileAccessI(String sName,long nPos) throws IOException U~pV)J
{ () j=5KDu
oSavedFile = new RandomAccessFile(sName,"rw"); )kP5u`v
this.nPos = nPos; '_V2!?+RU+
oSavedFile.seek(nPos); t^w"w`v\u
} p\bDY
xXM{pd
utIX %0
public synchronized int write(byte[] b,int nStart,int nLen) Nqu>6^-z0
{ }K&7%N4LZ
int n = -1; e d<n9R
try{ ]w.;4`l*
oSavedFile.write(b,nStart,nLen); 78/Zk}I]
n = nLen; 9]@A]p!
} d+'p@!W_
catch(IOException e) bFW=ylF9
{ @7B$Yy#
e.printStackTrace (); .C--gQpIv
} (;q;E\Ejq
rYbpih=x
({q?d[q[
return n; 6q{HU]N+
} 6Udov pl
B&@?*^.
oZAB_A)[-
} <TP=oq?I/
l6d$V9A
IP(Vr7-v
/* L|,!?cSAT
**SiteInfoBean.java ;UfCj5`Q)4
*/ ypy68_xyW
package NetFox; PS[+~>%
mFi&YpHu3
S;)w.
public class SiteInfoBean { 6Aku1h
tQjLOv+?=
@~%r5pz6
private String sSiteURL; //Site's URL kOed ]>H
private String sFilePath; //Saved File's Path (JM5`XwM
private String sFileName; //Saved File's Name 9o+)?1\
private int nSplitter; //Count of Splited Downloading File QDhOhGK
JhLgCnm
T7#W0^tj
public SiteInfoBean() 07[_.i.l
{//nSplitter的缺省值为5 o}$EG
//default value of nSplitter is 5 VSSu&Q
this("","","",5); Ba!J"b]
} *3?'4"B{8
Dp':oJC
iB498t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3J5!oF{H
{ 'JRvP!]
sSiteURL= sURL; 2'W<h)m)z
sFilePath = sPath; >Vwc3d
sFileName = sName; hK_LEwd;
this.nSplitter = nSpiltter; <?@NRFTe
rsy'q(N[
F 9@h|#an
} sn)3ZA
zaK#Z?V}
{$wjO7Glp
public String getSSiteURL() D`$hPYK|_
{ -&-Ma,M?
return sSiteURL; apu4DAy&8
} o/+13C
SF>c\eTtx
c5u@pvSP
public void setSSiteURL(String value) cj1cZ-
{ ekWePL;rR2
sSiteURL = value; f>N!wgo[
} wwyPl
#N`~xZ|$
*exS6@N]
public String getSFilePath() e8GEoD
{ K~| 4[\
return sFilePath; * iF]n2g:
} !y@6Mm
CW,Wx:Y
l\@)y4 +
public void setSFilePath(String value) ::}{_ Z
{ s;6CExH
sFilePath = value; FgB&b
} l=v4Fa0^jF
}Nf%n@
H{=21\a\
public String getSFileName() uLWh|
{ E(Z8
return sFileName; mD^jd+
} n\^Tq<] a
LILQ\I<<'
3GUZ;jdn
public void setSFileName(String value) /\4'ddGU
{ C,v(:ZE$J7
sFileName = value; vy\RcP
} .8by"?**
DF*:_B)
,f[>L|?e
public int getNSplitter() Z)SY.iK.
{ +Zaj,oEE
return nSplitter; `1bv@yzq
} !Rhlf.x
,}K7Dg^1
>kW@~WDMu
public void setNSplitter(int nCount) oz}+T(@O
{ 9f<MQ6_UU
nSplitter = nCount; }<9cL'
} TzNn^ir=HX
} $3s@}vLd
{/ BT9|LI
"gDb1h)8
/* =*r])Vg^
**Utility.java osX8eX]\
*/ RsY3V=u
package NetFox; 'qOREN
fmb} 2h
"HDcmIXg&
public class Utility { @tZ&2RY1
^h"`}[+
?'KL11@R
public Utility() @NNq z
{ SV~cJ]F
#0y)U;dA+w
\cUC9/ b
} +O*/"]h
+7=K/[9p
//线程睡眠 z<##g
public static void sleep(int nSecond) mjKS{
{ Yd#/1!A7u
try{ B(n{e53 9f
Thread.sleep(nSecond); hHT_V2*
} z$?~Y(EY
catch(Exception e) f]\CD<g3|E
{ <U!`J[n%
e.printStackTrace (); 4Za7^c.
} 8&)DE@W
} WRrd'{sB
vJ-q*qM1
//日志 ~;#Y9>7\\'
public static void log(String sMsg) >o7n+Rb:
{ 29?,<bB)
System.err.println(sMsg); 3tZ]4ms}
} 98uV6b~g
2gCX}4^3b
'8{Ne!y
public static void log(int sMsg) -\ EP.Vtz
{ +/)#( j@
System.err.println(sMsg); S|]X'f
} 4'!c*@Y
} ?C&z]f3(:
K0}pi+=
JU^lyi!
/* ]Zyur`
**TestMethod.java dAkgR~
*/ VBcy9|lD
package NetFox; :"xzj<(
y*tZ !m2Gg
2M68CE
public class TestMethod { 7]||UuF<
S'_-G;g.
7:)n$,31FW
public TestMethod() s3R(vd
{ ///xx/weblogic60b2_win.exe %sX$nmi3
try{ =p=rg$?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d\ 1Og\U|A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qT`k*i?
SiteFileFetch fileFetch = new SiteFileFetch(bean); %Ntcvp)
fileFetch.start(); N#DYJ-~*
} &' Ne!o8
catch(Exception e){e.printStackTrace ();} b;cdIl!3
C0}IE,]
bdF.qO9
} /$'AjIg4:&
3~S8!nx
EioB%f3
public static void main(String[] args) 9&` 2V
{ b/{t|io{
new TestMethod(); .tzG_
} :]^P1sH[
} [5+}rwm&W
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