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)); <m80e),~
} D!~-53f@
for(int i=0;i<nEndPos.length-1;i++) $@t-Oor;
{ S"UFT-N
nEndPos = nStartPos[i+1]; .foM>UOY
} jl=<Q.Mm7
nEndPos[nEndPos.length-1] = nFileLength; j3rBEQ,R
} 2@o_7w98
} DA@YjebP'
0sRby!
RR><so%
//启动子线程 #{GUu',?&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |*7uF<ink6
for(int i=0;i<nStartPos.length;i++) u7&r'rZ1_!
{ >'/G:\M>A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), su(y*187A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H>e?FDs0*R
nStartPos,nEndPos,i); S?%V o* Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YZf<S:
fileSplitterFetch.start(); REhXW_x
} viAvD6e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), phUno2fH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r+0"1\f3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;"&^ckP
nEndPos = " + nFileLength); 2s;/*<WM
// fileSplitterFetch[nPos.length-1].start(); I~MBR2$9
yE-&TW_q:>
@dcT8 YC
//等待子线程结束 9tXLC|yl?
//int count = 0; *"0Yr`)S
//是否结束while循环 ,qpn4`zE~
boolean breakWhile = false; ,-t3gc1~X
J /'woc
q,2]]K7y
while(!bStop) `|i #)
{ ` &|Rs
write_nPos(); z?h\7 R
Utility.sleep(500); x$AF0xFO
breakWhile = true; qJFBdJU(1
"tUXYY
1^R@X
for(int i=0;i<nStartPos.length;i++) 6!/e_a
{ 1&Rz'JQ+
if(!fileSplitterFetch.bDownOver) +}>whyX1
{ Q$W0>bUP
breakWhile = false; 31wact^
break; =+97VO(w]G
} B @UaaWh
} 'rRo2oTN
if(breakWhile) rOB-2@-
break; xzy7I6X
,Vt7Kiu
' G-]>
//count++; a|32Pn
//if(count>4) Rs{L
// siteStop(); Qwk
} oKz|hks[6
Uq~{=hMX
|h*H;@$
System.err.println("文件下载结束！"); (}"r 5
} s7SW4ff1
catch(Exception e){e.printStackTrace ();} 4kNf4l9Y
} BkJV{>?_+
HLAWx/c,j"
3ZU`}
//获得文件长度 \S}&QV
public long getFileSize() &m`1lxT
{ vML01SAi
int nFileLength = -1; ,2[laJ
try{ u1ggLH!U
URL url = new URL(siteInfoBean.getSSiteURL()); e1S |&W8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vX)JJ|g
httpConnection.setRequestProperty("User-Agent","NetFox"); 4/S4bk*8
7h<Q{X<A
LSNa
int responseCode=httpConnection.getResponseCode(); %U)/>Z
if(responseCode>=400) $91c9z;f^
{ 22`W*e@6h
processErrorCode(responseCode); p<'#f,o
return -2; //-2 represent access is error 8Cs)_bj#!
} q0.+F4
{IYfq)c
gf2l19aP
String sHeader; @YMef`T:
G7pj.rQ
8}\VlH]
for(int i=1;;i++) .Frc:Y{
{ 782be-n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `&4L'1eF{
//Utility.log(in.readLine()); K!5QFO4
sHeader=httpConnection.getHeaderFieldKey(i); 234OJ?
if(sHeader!=null) F5gL-\6
{ ?7@B$OlU
if(sHeader.equals("Content-Length")) j=r`[Bm
{ c#$B;?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0V"r$7(}
break; :qc@S&v@]
} XN5EZ#
} 8*H-</ =
else \ZigG{
break; S WVeUL#5
} =2\k Jv3
} nY'0*:'u
catch(IOException e){e.printStackTrace ();} 1<fS&)^W
catch(Exception e){e.printStackTrace ();} y!6B Gz
ANc)igo
kTAb <
Utility.log(nFileLength); ixw3Z D(>+
&xgMqv2/
s-}|_g.Pt
return nFileLength; JWr:/?
} bA@!0,m
tU>wRw=d
G6w&C^J*8>
//保存下载信息（文件指针位置） A9Q!V01_
private void write_nPos() F.HD;C-;(
{ V'#dY~E-P
try{ _~&6Kb^*
output = new DataOutputStream(new FileOutputStream(tmpFile)); *$Z}v&-0k
output.writeInt(nStartPos.length); iN"kv
for(int i=0;i<nStartPos.length;i++) JC(rSs*
{ $/Gvz)M
// output.writeLong(nPos); VJDF/)X3$
output.writeLong(fileSplitterFetch.nStartPos); >E|@3g +2
output.writeLong(fileSplitterFetch.nEndPos); GRB/N1=
} `$ZX]6G
output.close(); Y|_#yb
} MGfDxHg]
catch(IOException e){e.printStackTrace ();} @HxEp;*NH"
catch(Exception e){e.printStackTrace ();} 6b~Zv$5^Y-
} n`2d
c$rkbbf~V
0Jm6 r4s?
//读取保存的下载信息（文件指针位置） KiT>W~
private void read_nPos() ,aeQXI#@
{ 8;ke,x
try{ S(.AE@U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iE=Yh
int nCount = input.readInt(); =<e|<EwSZ
nStartPos = new long[nCount]; (wEaa'XL
nEndPos = new long[nCount]; L@HPU;<
for(int i=0;i<nStartPos.length;i++) l_hM,]T0
{ P,k~! F^L
nStartPos = input.readLong(); swYlp
nEndPos = input.readLong(); kQ7$,K#
} WjW+EF8(
input.close(); 0^az<!!O#
} :tp2@*]9Z
catch(IOException e){e.printStackTrace ();} =@AWw:!:,
catch(Exception e){e.printStackTrace ();} V&;1n
} J 05@SG':
a|SgGtBtT4
Rq )&v*=
private void processErrorCode(int nErrorCode) [9(tIb!x
{ t.$3?"60~
System.err.println("Error Code : " + nErrorCode); H;s
} CnSfGsE>
hEi]-N\X
'iA#lKG
//停止文件下载 GwQW I]
public void siteStop() k__iJsk
{ XAwo~E
bStop = true; oGM Ls
for(int i=0;i<nStartPos.length;i++) A-^[4&rb
fileSplitterFetch.splitterStop(); Q1jU{
Ig}G"GR
lT#&\JQ
} k"\%x=#
} 6!dbJ5x1
//负责部分文件的抓取 k!3X4;F!_
**FileSplitterFetch.java |t+M/C0y/
*/ g6{.C7m
package NetFox; .<`i!Ls
ig<Eyr
[zl@7X1{_
import java.io.*; _8P"/( `Rw
import java.net.*; ) DXN|<A
0]4kR8R3[
gD10C,{
public class FileSplitterFetch extends Thread { {a^A-Xh[u
0B fqEAl
o(w!x!["
String sURL; //File URL k4fc5P
long nStartPos; //File Snippet Start Position .) uUpY%K^
long nEndPos; //File Snippet End Position B4yU}v
int nThreadID; //Thread's ID *GleeJWz
boolean bDownOver = false; //Downing is over 74Xk^8
boolean bStop = false; //Stop identical PtCO';9[
FileAccessI fileAccessI = null; //File Access interface NAjY,)>'K
G6(kwv4
Rt:k4Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Yv k Qh{
{ d~F`q7F'?]
this.sURL = sURL; ^`~M f
this.nStartPos = nStart; _;(`u!@/{
this.nEndPos = nEnd; ]Q,;5>#W
nThreadID = id; /_<`#?5T(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3[I; 3=O
} _G%]d$2f`
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W&CQ87b
public void run() <k?ofE1o
{ b~fX=!M
while(nStartPos < nEndPos && !bStop) A<P3X/i
{ bwo-9B
KiYO,nD;\
1c_gh12
try{ q9fCoz
URL url = new URL(sURL); 'QGacV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B?Ac
httpConnection.setRequestProperty("User-Agent","NetFox"); KwK[)Cvv
String sProperty = "bytes="+nStartPos+"-"; x{{QS$6v
httpConnection.setRequestProperty("RANGE",sProperty); !$Aijd s5
Utility.log(sProperty); ]T|9>o!
Xou1X$$z
[p[nK=&r
InputStream input = httpConnection.getInputStream(); j(^ot001%v
//logResponseHead(httpConnection); (Cjnf a 2
^7MhnA
n@n608
byte[] b = new byte[1024]; d]1%/$v^
int nRead; J$6h%Eyo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zvjVM"=G
{ ah<1&UG,
nStartPos += fileAccessI.write(b,0,nRead); I@Zd<Rn
//if(nThreadID == 1) h/~:}Bof
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _svEPHU
} Y.` {]rC
5v"r>q[ X
W}m-5L
Utility.log("Thread " + nThreadID + " is over!"); s2f95<B
bDownOver = true; q-s! hiK
//nPos = fileAccessI.write (b,0,nRead); ?#8',:
} m|q?gX9R
catch(Exception e){e.printStackTrace ();} ^0"^Xk*
} AA][}lU:5
} ~\= VSwJ
*hVbjI$
\b{Aj,6,
//打印回应的头信息 Jf\lnJTyU8
public void logResponseHead(HttpURLConnection con) x._IP,vRx^
{ ?^Sk17G
for(int i=1;;i++) XL[/)lX{
{ gcYx-gA}
String header=con.getHeaderFieldKey(i); _&S?uz m
if(header!=null) 9pPb]v,6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B$~oZ'4v
Utility.log(header+" : "+con.getHeaderField(header)); 8N<0|u
else #Mo`l/Cwp
break; %bI(
} [NcS[*qp
} 6BIP;, M=
^l1tQnj)7
n^|;J*rD
public void splitterStop() ~;St,Fw<<
{ `@GqD
bStop = true; 5 e:Urv77
} mhnjYK9
(H*-b4]/
&tY3nr
} H+ra w/"
@rs(`4QEh
FFXDt"i2
/* TJ(PTB;
**FileAccess.java NfLvK o8
*//文件访问(定位，写) U$a Eby.
package NetFox; iO=xx|d
import java.io.*; 8+vZ9!7
tq=1C=h
1@IRx{v$
public class FileAccessI implements Serializable{ 0z?b5D;
K%LDOVE8e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'G6TSl
RandomAccessFile oSavedFile; eydVWVN
long nPos; $mm =$.
*Yv"lB8
4mOw[}@A
public FileAccessI() throws IOException !f_GR Pj'
{ &_FNDJ>MCk
this("",0); Rde_I`Ru
} m%V+px
3ojK2F(1D
Wu)ATs}
public FileAccessI(String sName,long nPos) throws IOException o;Ijv\Em
{ Hxr2Q]c?u
oSavedFile = new RandomAccessFile(sName,"rw"); b3b 4'l
this.nPos = nPos; %sC,;^wla'
oSavedFile.seek(nPos); oTtmn, T
} tW5\Ktjno
H%7V)"
>`*iM
public synchronized int write(byte[] b,int nStart,int nLen) Ff>Y<7CQ v
{ Y~1}B_
int n = -1; VL5kjF3/
try{ l^xkXj
oSavedFile.write(b,nStart,nLen); ~l!(I-'?g
n = nLen; *pP"u::S
} A(_AOoA'
catch(IOException e) e<5+&Cj
{ IcL3.(!]l
e.printStackTrace (); !boKrSw
} 0w\X
j>&n5?
`'Ta=kd3
return n; )xQxc.
} ^a; V-US
xmKa8']x
==x3|^0y
} qNHS 1
UEo,:zeN[
jbIWdHZ/US
/* .u7d
**SiteInfoBean.java rQ}4\PTi
*/ B0p>'O2
package NetFox; uW>AH@Pij
/p\Ymq
'5ky<
public class SiteInfoBean { (m;P,*
;YZw{|gsh
("/*k
private String sSiteURL; //Site's URL IX7d[nm39
private String sFilePath; //Saved File's Path 0nx <f>n
private String sFileName; //Saved File's Name I-/PzL<W P
private int nSplitter; //Count of Splited Downloading File gY0*u+LF
6FEtq,;0w
pMt]wyKr
public SiteInfoBean() wT*N{).
{//nSplitter的缺省值为5 Jq6p5jr"
//default value of nSplitter is 5 [-6j4D
this("","","",5); LV8,nTYvE
} @Jm$<E
}QJE9;<e
,6t0w|@-k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yrsP'th
{ 0@AK
sSiteURL= sURL; ; UrwK
sFilePath = sPath; ?rBj{]=
sFileName = sName; CKh-+8j
this.nSplitter = nSpiltter; (|U+(~PJ
`dL9sfj>
"#4PU5.
} ev8E.ehD
bO2$0!=I
6Ir ?@O1'!
public String getSSiteURL() 6bb=;
{ TqQ>\h"&_
return sSiteURL; |AFF*]e S
} 1GEE^Eu
WX0@H[$i#
:eIBK
public void setSSiteURL(String value) 7FMHz.ZRE
{ ; $y.+5 q
sSiteURL = value; sXhtn'<v
} +,|-4U@dl
)3..7ht3^5
8<]>q
public String getSFilePath() 6eS#L21*
{ (9cIU2e
return sFilePath; (b{ {B$O
} RIJBHOa
e9%6+9Y
{Or|] 0
public void setSFilePath(String value) w:umr#
{ *E$D,
sFilePath = value; sL\|y38'
} <c\aZ9+V
$iP#8La:Y
ax3:rl
public String getSFileName() x65e,'
{ @{nT4{
return sFileName; (O<lVz@8
} RuXK` ySv
=vK(-h
u5,IH2BU
public void setSFileName(String value) ntF(K/~Y
{ ' l!QGKz
sFileName = value; Zv-6H*zM6
} KGI]W|T
ZO;]Zt]
6Edqg
public int getNSplitter() 'PO1{&M
{ j2\G1@05
return nSplitter; ~]yqJYiid^
} 9<YB&:<
A5/h*`Q\\
ILVbbC`D
public void setNSplitter(int nCount) X<?;-HrS;
{ V2y[IeSQ
nSplitter = nCount; D=OU61AA
} s e1ipn_A
} tou^p-)GQ|
zCQv:.0L
r;'!qwr
/* <B fwR$
**Utility.java +X?jf.4
*/ xz%ig^L
package NetFox; bc"{ZL!C
Vnl~AQfk|
K:Ap|F
public class Utility { @V-ZV
6%'{Cq1DE
3a5H<3w_
public Utility() <AIsNqr
{ K l4",
)N=wJN1
s R~&S))
} [:k'VXL
;'Y?wH[
//线程睡眠 \Dc\H)
public static void sleep(int nSecond) p<+]+,|\~:
{ X-duG*~
try{ Zb1v
Thread.sleep(nSecond); OYzJE@r^
} lAGxE-B^a"
catch(Exception e) .dfTv/n
{ =#u2Rx%V
e.printStackTrace (); b'&pJ1]]}
} }Q%>Fv
} m<yA] ';s
mSzwx/3"
//日志 _5)#{o<
public static void log(String sMsg) Brl6r8LGi
{ GGBe/X
System.err.println(sMsg); Y[H_?f=;%
} ^d"J2n,7L
Y}Dp{
oY]VP+b!
public static void log(int sMsg) Ao\Vh\rQkq
{ ^DH*@M
System.err.println(sMsg); EK'&S=]
} cU>&E*wD
} H )}WWXK
Z^|C~lp;n
e!8_3BE
/* y"hM6JI
**TestMethod.java rEf\|x=st:
*/ <\8
package NetFox; C0W~Tk\C2
Gh pd k;
t[maUy_A
public class TestMethod { D6]$P%t9
@r43F$bcqo
5 QeGx3'
public TestMethod() I Q L~I13
{ ///xx/weblogic60b2_win.exe %(Ys-GeGr
try{ n96gDH*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NQJqS?^W&M
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #R8l"]fxr?
SiteFileFetch fileFetch = new SiteFileFetch(bean); =tNiIU
fileFetch.start(); 8?YW i
} ##@#:B
catch(Exception e){e.printStackTrace ();} $iPN5@F
>FHsZKJ
jq]"6/xxb
} {|h"/
>>cd3)b
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public static void main(String[] args) 48Lmy<}*
{ `.W;ptZ6
new TestMethod(); D.o|($S0
} `Cf en8
} j*u9+.
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