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)); 0j_`7<,:
} G#3 O^,m
for(int i=0;i<nEndPos.length-1;i++) a&wl-
{ z9'ME
nEndPos = nStartPos[i+1]; a:v&pj+|<
} 3QU<vdtr
nEndPos[nEndPos.length-1] = nFileLength; ^5j9WV
} oT%~)g
} w+*Jl}&\
b!ot%uZZ
1i#M(u_
//启动子线程 |u7vY/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZU7,=B=
for(int i=0;i<nStartPos.length;i++) "P"~/<:)
{ |4ONGU*`E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J=|fxR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "qR qEpD%
nStartPos,nEndPos,i); ![{>f6{J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j01#Wq_\fk
fileSplitterFetch.start(); 1[:?oEI
} jrZM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yA \C3r'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V!a\:%#^Y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _l{GHz
nEndPos = " + nFileLength); 50uNgLs
// fileSplitterFetch[nPos.length-1].start(); Ef:.)!;jy
]k " j
x.xfMM2n
//等待子线程结束 egK,e?~
//int count = 0; s(r(! FZ
//是否结束while循环 <p-R{}8
boolean breakWhile = false; ~4`LOROC
XGbtmmQG
^<.mUaP
while(!bStop) OB>Pk_eQK
{ :,]V03
write_nPos(); Ky|dRbK,
Utility.sleep(500); {^1D|y
breakWhile = true; D42Bm&JocO
{%)bxk6
$*\[I{Zau}
for(int i=0;i<nStartPos.length;i++) @M?;~M?B]J
{ $NWXn,Y'
if(!fileSplitterFetch.bDownOver) vxzh|uF
{ nX7{09
breakWhile = false; Dny5X.8
break; ts<5%{M(
} ^dJ/>?1
} #tRLvOR:
if(breakWhile) kid3@
break; 4. 7m*
%V%*0S|U
\25Rq/&w
//count++; BA4qQCS;5
//if(count>4) EC<g7_0F
// siteStop(); m}54yo
} PO%Z.ol9
suC]
"94e-Nx
System.err.println("文件下载结束！"); xc7Wk&{=
} sgW*0o
catch(Exception e){e.printStackTrace ();} bS=aFl#
} -aK_
t:B~P,r
u[5*RTE
//获得文件长度 ~Gx"gK0
public long getFileSize() 2Dgulx5kGZ
{ ~>2@55wElp
int nFileLength = -1; 1S/KT4
try{ %C^U?m`
URL url = new URL(siteInfoBean.getSSiteURL()); P1tc*2Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D/[(}o(
httpConnection.setRequestProperty("User-Agent","NetFox"); dtD)VNkBZ
6c>cq\~E
p_pI=_:
int responseCode=httpConnection.getResponseCode(); SEu1M}+E
if(responseCode>=400) n]c6nX:'
{ /UtCJMQ
processErrorCode(responseCode); Z.TYi~d/9D
return -2; //-2 represent access is error ye!}hm=w
} //T1e7)
8@y@}
N.R,[K
String sHeader; LE#ko2#ke
g$$i WC!S<
s~(!m. R
for(int i=1;;i++) oRH]67(Z
{ l-4+{6lz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,tqMMBwC~_
//Utility.log(in.readLine()); wtlIyE
sHeader=httpConnection.getHeaderFieldKey(i); J=v" HeVm
if(sHeader!=null) |e49F
{ a k&G=a6^
if(sHeader.equals("Content-Length")) %N``EnF2
{ `P/7Mf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R <Mvwu
break; ^I2+$
} 3,;;C(
} +$_.${uwV
else J" :R,w`
break; sv}k_6XgY
} R)}ab{A
} 4I&e_b< 30
catch(IOException e){e.printStackTrace ();} %#7NCdk;S
catch(Exception e){e.printStackTrace ();} pYXusS7S
8['8ctX
vq(ElXTO
Utility.log(nFileLength); G!Gbg3:4e5
FZdZGK
2GRL`.1
return nFileLength; xcf`i:\
} _c:}i\8R
1^R[kaY
)H HBf<
//保存下载信息（文件指针位置） _'OXrT#Q
private void write_nPos() AW[_k%
{ IhRWa|{I
try{ <d`ksZ+
output = new DataOutputStream(new FileOutputStream(tmpFile)); L_ &`
output.writeInt(nStartPos.length); ,\".|m1o.
for(int i=0;i<nStartPos.length;i++) nogdOGo
{ CRpMpPi@}
// output.writeLong(nPos); {`KRr:w
output.writeLong(fileSplitterFetch.nStartPos); E$8D^Zt
output.writeLong(fileSplitterFetch.nEndPos); JSf \ApX
} (-e*xM m
output.close(); VyF|d?b
} BNj@~uC{
catch(IOException e){e.printStackTrace ();} &-e@Et`Pg
catch(Exception e){e.printStackTrace ();} =PQMd
} )fGIe rS
()\=(n!J
655OL)|cD6
//读取保存的下载信息（文件指针位置） ]i)g!J8f-
private void read_nPos() 16cc9%
{ O/{X:Ja{
try{ vGST{Lz;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @)^|U"
int nCount = input.readInt(); O~udlVn<6
nStartPos = new long[nCount]; e]!`Cl-f80
nEndPos = new long[nCount]; Kn#CIFbBN
for(int i=0;i<nStartPos.length;i++) VnU/_#n
{ 1+Z@4;fk
nStartPos = input.readLong(); kWZ@v+Mk3
nEndPos = input.readLong(); *mVQN1
} V1]QuQ{&s
input.close(); gXb * zt2
} %@,! (
catch(IOException e){e.printStackTrace ();} (\zxiK
catch(Exception e){e.printStackTrace ();} z&Kh$ $)[
} 6o cTQ}=
S}}L& _
FpYeuH%
private void processErrorCode(int nErrorCode) Hl*V i3bQU
{ s~tZN
System.err.println("Error Code : " + nErrorCode); d"nms\=p
} {yCE>F\
q L-Ni
E=&":I6O
//停止文件下载 \b6vu^;p
public void siteStop() %8hx3N8>
{ N2Qb+
bStop = true; x1'4njTV$
for(int i=0;i<nStartPos.length;i++) S0]JeP+3!
fileSplitterFetch.splitterStop(); gK_#R]
&VdKL2
}9*NEU)o
} x T{s%wE
} #!>QXiyR
//负责部分文件的抓取 1x3>XN]a
**FileSplitterFetch.java FE4P EBXvu
*/ \<kQ::o1y
package NetFox; 9 .3?$(
m> YjV>5
/DGEI&}&:u
import java.io.*; XbYST%|.
import java.net.*; |Ca %dg9$@
H9Dw#.em
4%"Df1U
public class FileSplitterFetch extends Thread { mXK7y.9\
Zk<Y+!
v"8i2+j
String sURL; //File URL pp1kcrE\M
long nStartPos; //File Snippet Start Position &j!q9F
long nEndPos; //File Snippet End Position *OU&`\bmE
int nThreadID; //Thread's ID ?atHZLF
boolean bDownOver = false; //Downing is over \L:+k `
boolean bStop = false; //Stop identical )>r sX)
FileAccessI fileAccessI = null; //File Access interface V: P
,UATT]>
3,dIW*<**
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fb_q2p} G
{ -40s
this.sURL = sURL; @E%fAC
this.nStartPos = nStart; 0kxe5*-|
this.nEndPos = nEnd; /:+MUw7~
nThreadID = id; 8umW>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;9)A+bD]
} dCO7"/IHW
Nf1&UgX
<uXQT$@?
public void run() 9ohO-t$XkY
{ V1 {'d[E*
while(nStartPos < nEndPos && !bStop) 6e4A|<
{ ur JR[$p
q?=_{oH9
"VI2--%v3
try{ (Nn)_caVb
URL url = new URL(sURL); (5efNugc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (&oT6Ji
httpConnection.setRequestProperty("User-Agent","NetFox"); Ch7&9NW
String sProperty = "bytes="+nStartPos+"-"; Np>0c-S
httpConnection.setRequestProperty("RANGE",sProperty); 0ra+MQBg
Utility.log(sProperty); K/|qn)
Y8Z-m (OQ
}cd-BW
InputStream input = httpConnection.getInputStream(); Wf>=^ ~`
//logResponseHead(httpConnection); %+ur41HM
P.'$L\
}ZkGH}K_}
byte[] b = new byte[1024]; Ie'iAY
int nRead; IIUTo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) drd5oZ
{ 8 _|"+Ze
nStartPos += fileAccessI.write(b,0,nRead); TF-a1z
//if(nThreadID == 1) Oi$$vjs2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z2god 1"
} WlRaD%Q
mL3 Q
*ez7Q
Utility.log("Thread " + nThreadID + " is over!"); UjcKvF
bDownOver = true; (tzfyZ M
//nPos = fileAccessI.write (b,0,nRead); {IT;g9x
} by*v($
catch(Exception e){e.printStackTrace ();} /9(8ML#E
} *(j-jbA
} D~r{(u~Ya
!= u S
j\TS:F^z
//打印回应的头信息 e|Mw9DIW
public void logResponseHead(HttpURLConnection con) 2X|nPhNi
{ _v +At;Y
for(int i=1;;i++) w02t9vz
{ 7^n{BsN
String header=con.getHeaderFieldKey(i); eZ;DNZK av
if(header!=null) &d i=alvv1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QI{<q<
Utility.log(header+" : "+con.getHeaderField(header)); @+(a{%~7y
else 6M X4h
break; kd+tD!:F(
} 8e}8@[h
} %\?Gzc_
&~sk7iGi
ZY-mUg
public void splitterStop() '~OKt`SfIo
{ &T[BS;
bStop = true; w$FN(BfA
} ;ksxz
_Rey~]iJJ8
*D;VZs0O
} LAPCL&Z
Mp)|5<%
QliP9-im3
/* ]-tAgNzl%
**FileAccess.java @ )m9#F
*//文件访问(定位，写) FaA7m
package NetFox; V9<CeTl'
import java.io.*; kJ:zMVN
[Se0+\,&
jG~UyzWH;
public class FileAccessI implements Serializable{ ?,Zc{
ybgAyJ{J<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W.VyH|?
RandomAccessFile oSavedFile; :R9 DJh\
long nPos; "Go)t+-
+Y|HO[
jj*e.t:F
public FileAccessI() throws IOException NJTC+`Hm
{ 32ae? d
this("",0); 6N]V.;0_5
} +)7Yqh#$
ufWd)Q
5,1q%
public FileAccessI(String sName,long nPos) throws IOException .3*VkAs
{ =| M[JPr
oSavedFile = new RandomAccessFile(sName,"rw"); A1nEp0%Y
this.nPos = nPos; )XAD#GYM
oSavedFile.seek(nPos); Il9pL~u
} 4Iou| H
2e @zd\
7Vxe]s
public synchronized int write(byte[] b,int nStart,int nLen) ua!g}m~
{ IRW%*W#
int n = -1; Uv"GG: K_
try{ xr\wOQ*`
oSavedFile.write(b,nStart,nLen); >o"3:/3
n = nLen; 34P5[j!h
} qg;fh]j%
catch(IOException e) Y8yRQzu
{ "x$RTuWA9
e.printStackTrace (); $@blP<I
} ^"d!(npw
);.q:"
e!(0y)*
return n; zu Jl #3YP
} t"@:a Y"
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Eb<iR)e H=
} F+@E6I'g
K$..#]\TM
"A_WU|
/* $LF
**SiteInfoBean.java hL,+wJ+A
*/ sgn,]3AUq
package NetFox; 6_wf $(im
icf[.
syYg, G[
public class SiteInfoBean { !m#cneV
Gd~Xvw,u
AVR9G^ce_
private String sSiteURL; //Site's URL %8T:rS
private String sFilePath; //Saved File's Path "kKIVlC
private String sFileName; //Saved File's Name rZy38Wo
private int nSplitter; //Count of Splited Downloading File "b!QE2bRO
SrN;S kS
g]V}azLr
public SiteInfoBean() 1@Bq-2OD4
{//nSplitter的缺省值为5 ?'K}bmdt}.
//default value of nSplitter is 5 0C}7=_?
this("","","",5); MO:##C
} QK\QvU2y
}B_n}<tjD
.e2u)YqA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?rQMOJR
{ ,sk;|OAI
sSiteURL= sURL; '?5=j1
sFilePath = sPath; *0y+=,"QU
sFileName = sName; ?kew[oZ
this.nSplitter = nSpiltter; 6-#f1D 6
qoMYiF}/e
DFs J}` $
} yg "u^*r&
Etj*3/n|
A^JeB<, 5a
public String getSSiteURL() <>f
{ M%:ACLYP
return sSiteURL; ' %OQd?MhL
} }VE[W
O!zH5
e+=Ojo#
public void setSSiteURL(String value) kRskeMr:Rd
{ qqSk*oH~
sSiteURL = value; T IPb ]
} uG3t%CmN
pN&Dpz^
g!7/iKj:
public String getSFilePath() DT(A~U<y
{ v|jBRKU99
return sFilePath; E`>-+~ZUsk
} 9p(s FQ [
.*D~ .!
E/(:\Cm^
public void setSFilePath(String value) KS'? DO
{ 4D[W;4/p
sFilePath = value; -) $$4<L
} zb~!> QIz{
/bVU^vo
S8<O$^L^
public String getSFileName() _=j0Y=/IF
{ bR49(K$~
return sFileName; ^Ebaq`{V\'
} x!MYIaZ7
of8/~VO
UBi0 /
public void setSFileName(String value) +|Xx=1_?BK
{ rayC1#f
sFileName = value; ?bQ~+M\
} Az6f I*yP
_7]* 5Pxo
j*g5f
public int getNSplitter() WU{G_Fqaz
{ $~50M5&K#
return nSplitter; Oh~JyrZy
} bKmR &
v%=G~kF}[
.!,T>:R
public void setNSplitter(int nCount) e0+N1kY
{ A"#Gg7]tl'
nSplitter = nCount; n'1pNL:
} 28LjQ!
} <y\>[7Y
L$l'wz
G*mk 19Z
/* {Aj}s3v
**Utility.java !tmY_[\
*/ Dx/?0F7V
package NetFox; lzfaW-nu
zOCru2/
-JaC~v(0
public class Utility { tV@!jaj\
7 \!t/<
C*b!E:
public Utility() zy8W8h(?
{ +I5@Gys
eL#pS=
,S2D/Y^>
} H{E223
d5\w'@Di
//线程睡眠 c@~\ FUr
public static void sleep(int nSecond) 7z)Hq./3@
{ BE:HO^-.1
try{ ; GRSe
Thread.sleep(nSecond); #)tt}GX
} 7*M+bZ`x
catch(Exception e) ckBcwIXlP&
{ 8U*}D~%!
e.printStackTrace (); siZw-.
} X.}:gU-
} O2us+DhQ
lSUEE0V%Q
//日志 Jp!Q2}
public static void log(String sMsg) g599Lc&
{ vkOCyi?c
System.err.println(sMsg); x}i:nLhL
} \&`S~cV9
H.hF`n
>>Z.]
public static void log(int sMsg) T' %TMA
{ |#LU"D
System.err.println(sMsg); GP<A v1
} 9sFZs]uM
} G}&B{Ir
e]'ui<`
6x^#|;e>lI
/* y-)|u:~h
**TestMethod.java &{]zL
*/ HbX>::J8
package NetFox; ^J< I Ia4
WOrz7x
)AEJ`xC
public class TestMethod { G?jKm_`L
PF2PMEBx!
*R m>bLI
public TestMethod() 75u/'0~5
{ ///xx/weblogic60b2_win.exe D kl4^}
try{ JQj?+PI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4%LGPh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); WolkW:(Cg
SiteFileFetch fileFetch = new SiteFileFetch(bean); :Gsh
fileFetch.start(); [KLs} ~H
} `|Pfa
catch(Exception e){e.printStackTrace ();} 5f(yF
SpU+y|\[0
Wl/oun~o
} 7+0Kg'^+n
c3W9"
y4PR&^l?g
public static void main(String[] args) 'c*Q/C;
{ ~,WG284
new TestMethod(); qT$;ZV #
} Aw~ =U!
} rU=qr&f"B
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