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)); 5bmtUIj
} AH=6xtS-
for(int i=0;i<nEndPos.length-1;i++) H3OH
{ `!m+g0
nEndPos = nStartPos[i+1]; 4B]8Mp~\aL
} lt0(Kf g
nEndPos[nEndPos.length-1] = nFileLength; _Zf1=&U#/
} D zDt:.JZ
} m U7Ad"
>47,Hq:2
Zb2 B5(0
//启动子线程 d:sUh
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b@,=;Y)O
for(int i=0;i<nStartPos.length;i++) C?x
{ P!bm$h*3?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D"1ciO8^I]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), UQW;!8J#R(
nStartPos,nEndPos,i); nsgNIE{>gO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &2?kD{
fileSplitterFetch.start(); k_}ICKzw1
} \UB<'~z6!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sOJ"~p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yMz@-B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Uk*s`Y
nEndPos = " + nFileLength); (Z`Y
// fileSplitterFetch[nPos.length-1].start(); kf5921(P
}P}l4k1W
kFk+TXLDIt
//等待子线程结束 \D}/tz5~B
//int count = 0; nh9K(
//是否结束while循环 |Z2_1( ku
boolean breakWhile = false; 2N)vEUyDV
.WG@"2z|
pbm4C0W}
while(!bStop) (\R"v^
{ #lVVSrF,-
write_nPos(); CtSAo\F
Utility.sleep(500); qVM]$V#e
breakWhile = true; b|fq63ar;
CB|z{(&N
i1G}mYz_
for(int i=0;i<nStartPos.length;i++) EKoCm)}d
{ vkR"A\:
if(!fileSplitterFetch.bDownOver) g?@(+\W
{ 2,_BO6 !d
breakWhile = false; =~HX/]zF
break; )(!vd!p5
} HDy[/7"
} MCYrsgg}
if(breakWhile) V@Po}
break; a<\m` Es=
O9>/WmLe
jliKMd<?
//count++; l{y~N
//if(count>4) 14^t{
// siteStop(); 7z+NR&'M$
} t~bjDV^`
U\b,W&%P
a{u)~:/G
System.err.println("文件下载结束！"); MOOL=Um3
} =n#xnZ3
catch(Exception e){e.printStackTrace ();} %l5J
} FNm8j#c~Q
'rCwPsI&4
}S42.f.p
//获得文件长度 Ii,L6c
public long getFileSize() *?i~AXJm
{ E&"bgwav{(
int nFileLength = -1; lFRgyEPH
try{ #FeM.k6
URL url = new URL(siteInfoBean.getSSiteURL()); thq(tK7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2#py>rF(
httpConnection.setRequestProperty("User-Agent","NetFox"); 4lz9z>J.V
L;v#9^Fq
:/1WJG:!
int responseCode=httpConnection.getResponseCode(); z1YC%Y|R
if(responseCode>=400) +i K.+B
{ @s@r5uR9B
processErrorCode(responseCode); pG|DT ?
return -2; //-2 represent access is error `[`eg<xj
} wRWN]Vo
EW YpYMkm
#&$4tTl
String sHeader; CaK 0o*D
q`qbaX\J3
"S6d^
for(int i=1;;i++) /dtFB5Z"w
{ <ZCjQkka>r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); EpPKo
//Utility.log(in.readLine()); 7<X_\,I
sHeader=httpConnection.getHeaderFieldKey(i); g.z/%LpK
if(sHeader!=null) .PF~8@1ju
{ 5 kQC
if(sHeader.equals("Content-Length")) /pV^w
{ C/lpSe
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E?%rmdyhL!
break; zi<C5E`
} rw58bkh6
} .,feRK>3
else P PmE.%_
break; >a]{q^0
} ?|{P]i?)'
} OCF=)#}qd
catch(IOException e){e.printStackTrace ();} [_CIN
catch(Exception e){e.printStackTrace ();} fF<~2MiKw
UKn>.,
&(irri_
Utility.log(nFileLength); joYj`K
@7.Ews5Mke
1[mX_ }K
return nFileLength; wR\%tumk
} +.gZILw
PC=b.H8P+W
$M#G;W5c
//保存下载信息（文件指针位置） $xNZ.|al
private void write_nPos() ,D;d#fJ
{ }eSaF@.
try{ -PoW56
output = new DataOutputStream(new FileOutputStream(tmpFile)); arET2(h
output.writeInt(nStartPos.length); D8G5,s-.
for(int i=0;i<nStartPos.length;i++) `Z0FQ( r_
{ AwUcU;"9>
// output.writeLong(nPos); $CRu?WUS]'
output.writeLong(fileSplitterFetch.nStartPos); !CY:XQm
output.writeLong(fileSplitterFetch.nEndPos); d3<7t
} Qw}uB$S>
output.close(); 2old})CLJ
} ,F!zZNW9
catch(IOException e){e.printStackTrace ();} cY0NQKUk~
catch(Exception e){e.printStackTrace ();} #;z;8q
} jH({Qc,97
Uyj6Ij_Pj)
Vo"Wr>F
//读取保存的下载信息（文件指针位置） Nu/wjx$b
private void read_nPos() ~l+2Z4nV
{ ]{s0/(EA
try{ n 9PYZxy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s'b 4Me
int nCount = input.readInt(); J;|a)Nw
nStartPos = new long[nCount]; L7;8:^ v
nEndPos = new long[nCount]; L`NY^
for(int i=0;i<nStartPos.length;i++) uGOED-@
{ %PM&`c98z7
nStartPos = input.readLong(); ct`j7[
nEndPos = input.readLong(); ~@=(#tO.
} y)vK=,"
input.close(); :e/*5ix
} eu={6/O
catch(IOException e){e.printStackTrace ();} VK286[[fv
catch(Exception e){e.printStackTrace ();} :e1kpQ
} l0 =[MXM4
UE8j8U'L
>m]LV}">O
private void processErrorCode(int nErrorCode) iR?}^|]
{ )G#mC0?PV
System.err.println("Error Code : " + nErrorCode); @@JyCUd
} VWq]w5oQO
s@Dln Du.
7UIf
//停止文件下载 &^2SdF
public void siteStop() "i#aII+T
{ -M/j&<;LW
bStop = true; {ETM >
for(int i=0;i<nStartPos.length;i++) \~RDvsSD
fileSplitterFetch.splitterStop(); :of(wZa3Q
DA1?M'N
w 5 yOSz
} Z1#u&oX
} nr2 Q[9~
//负责部分文件的抓取 I4W@t4bZ
**FileSplitterFetch.java 1U% /~
*/ vJLGy]
package NetFox; j$K*R."
wA\5-C7j
DQT'OZ:w
import java.io.*; W1 k]P.
import java.net.*; c/Xg ARCO
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s$).Z(6
public class FileSplitterFetch extends Thread { +$|fUn{
1W\E`)Z}]
om`T/@_,
String sURL; //File URL DY -5(6X
long nStartPos; //File Snippet Start Position #=t/wAE y:
long nEndPos; //File Snippet End Position MjU|XQS:
int nThreadID; //Thread's ID =*&[K^
boolean bDownOver = false; //Downing is over y(o)}m*0
boolean bStop = false; //Stop identical w8XCU> |
FileAccessI fileAccessI = null; //File Access interface =e4 r=I
I]^>>>p$
@^A5{qQ\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,Klv[_x7
{ @^xtxtjzux
this.sURL = sURL; C,An\lsT
this.nStartPos = nStart; "!~o
this.nEndPos = nEnd; [ n7>g
nThreadID = id; CmZayV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s{-gsSmE
} I|U'@E
z Fo11;*D
f#=c=e-A
public void run() hbJ>GSoZ,
{ q0iJy@?A
while(nStartPos < nEndPos && !bStop) .!x&d4;,q
{ D7;9D*o\
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#;$]M4
try{ W6&vyOc
URL url = new URL(sURL); HeOdCr-PN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WwDM^}e
httpConnection.setRequestProperty("User-Agent","NetFox"); 2yZr!Rb~*
String sProperty = "bytes="+nStartPos+"-"; :OG I|[
httpConnection.setRequestProperty("RANGE",sProperty); @1MnJP
Utility.log(sProperty); Upe}9xf
`ePC$Ovn
w G%W{T$
InputStream input = httpConnection.getInputStream(); V)j[`,M:
//logResponseHead(httpConnection); zxbfh/=
X2z<cJG|d@
v $Iw?y
byte[] b = new byte[1024]; 4J2^zx,H
int nRead; KJA :;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <kak9 6A
{ JE=t e(a
nStartPos += fileAccessI.write(b,0,nRead); j3gDGw;
//if(nThreadID == 1) xu2KEwgb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T5(S2^)o
} 2 T!Tiu
'<R>cN"
9a}9cMJ^"
Utility.log("Thread " + nThreadID + " is over!"); Zt`Tg7m
bDownOver = true; CKYg!\g(:
//nPos = fileAccessI.write (b,0,nRead); GJ+^t
} ]~({;;3o-
catch(Exception e){e.printStackTrace ();} .ZpOYhk
} :DD<0
} Qp>leEs]+6
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J ^'El^F
//打印回应的头信息 Zxa.x?:?n
public void logResponseHead(HttpURLConnection con) t`Kbm''d[
{ 6b2UPI7m~
for(int i=1;;i++) szI7I$Qb
{ |9CikLX)7
String header=con.getHeaderFieldKey(i); I//=C6
if(header!=null) g.lTNQm$u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;<[X\;|'
Utility.log(header+" : "+con.getHeaderField(header)); =]Wi aF
else d*gAL<M7E
break; i5'&u:
} j~CnMKN
} XLNbV?
{]0e=#hw
$></%S2g
public void splitterStop() ?'a8QJo
{ JMb_00r
bStop = true; dftBD
} s]arNaaA
bSB%hFp=Cp
SmRlZ!%e
} 4,9$udiGY
6Sr]<I +:
fab'\|Y
/* ,X4e?$7g
**FileAccess.java jvzioFCt
*//文件访问(定位，写) #36QO
package NetFox; g^AQBF
import java.io.*; N[%u>!
wPA^nZ^}9c
U7r8FLl
public class FileAccessI implements Serializable{ PRKZg]?
o/5-T4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ex3Qbr
RandomAccessFile oSavedFile; *ByHTd
long nPos; *rxr:y#Ve
gFDnt
NYm"I`5w
public FileAccessI() throws IOException !`DRJ)h
{ I \:WD"
this("",0); <`H0i*|Ued
} ll:UIxx
ZnG.::&:
V Z(/g"9
public FileAccessI(String sName,long nPos) throws IOException YOCEEh?
{ $.G 7Vt
oSavedFile = new RandomAccessFile(sName,"rw"); Dl,QCZeM
this.nPos = nPos; yI0bSu<j-
oSavedFile.seek(nPos); 55[ 4)*
} t@q'm.:uw<
+H)'(<
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public synchronized int write(byte[] b,int nStart,int nLen) .Y)[c.,j
{ !Ok(mgV$/
int n = -1; -YRIe<}E -
try{ Q$jEmmm%V[
oSavedFile.write(b,nStart,nLen); Dk1& <} I
n = nLen; 5!-TLwl`j\
} Sg#XcTG
catch(IOException e) n3^(y"q
{ ho]:)!|VY
e.printStackTrace (); ui8 Q2{z
} Y\|#Lu>B
&C 9hT
3h@]cWp
return n; FpoHm%+
} P4zo[R%4
LPk@t^[
l_B735
} z>x@o}#u\|
G\.~/<Mg+
."Ms7=
/* *S$vSDJCW
**SiteInfoBean.java JA^o/%a^
*/ ^X#y'odtbS
package NetFox; RObnu*
-<iP$,bq72
@[GV0*yz$
public class SiteInfoBean { 6j#JhcS+
d2\!tJm
>{#JIG.
private String sSiteURL; //Site's URL %#6@PQ[R.
private String sFilePath; //Saved File's Path fFQ|dE;cF
private String sFileName; //Saved File's Name TlG>)Z@/
private int nSplitter; //Count of Splited Downloading File N&9o 1_}
2HbnE&
eUPa5{P
public SiteInfoBean() 9&mSF0q
{//nSplitter的缺省值为5 bO~y=Pa\
//default value of nSplitter is 5 mHD_cgKN
this("","","",5); eP{srP3 9
} J-W9Bamx
^-o{3Q(w
/:dLqyQ_V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }nmlN
{ 2YD\KXDo
sSiteURL= sURL; b@CB +8$
sFilePath = sPath; n1[c\1
sFileName = sName; t],a1I.gk
this.nSplitter = nSpiltter; <_?zln:4.
j,IRUx13f
!MbzFs~
} [%W'd9`>
Qg>NJ\*Q
STKL
public String getSSiteURL() 2TK \pfD
{ %?~'A59
return sSiteURL; &@=Jm /5
} }=R]<`Sj.j
\#sD`O
05UN <l]
public void setSSiteURL(String value) q0sf\|'<}
{ dFg>uo
sSiteURL = value; *TOdIq&z
} sXLW';Fz
>.:+|Br`
n@p]v*
public String getSFilePath() 9QZaa(vN
{ lu utyK!
return sFilePath; qF)J#$4;6
} u?').c4
awLvLkQb{
a~o<>H
public void setSFilePath(String value) XF`2*:7
{ A(Ct^/x-
sFilePath = value; b?wrOS
} Dy08.Sss
b,!C8rJ
!R{IEray
public String getSFileName() JsaXI:%1
{ ':4cQ4Z
return sFileName; ucCf%T\:
} ];bRRBEU
mh+T!v$[n)
ew;;e|24
public void setSFileName(String value) mF~T?L"
{ 7?lz$.*Avp
sFileName = value; Bk8}K=%w
} <JPN< Kv
cXweg;
,05PYBc3
public int getNSplitter() y<`5
{ LKN7Lkl
return nSplitter; @2(u=E:^
} )"x6V""Rb
c~|(j \FI
A|biOz
public void setNSplitter(int nCount) .:_'l)-
{ 3@Ndn
nSplitter = nCount; nnlj#
} Z[O hZ 9
} eqtZU\GI>
s.1F=u9a
m\teE]8x
/* "O$bq::(]e
**Utility.java G?4@[m
*/ O]:9va
package NetFox; tFU4%c7V
k@xinK%O{
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public class Utility { .jRI $vm
Y1r$;;sH
1UQ,V`y
public Utility() xU'z>y4V$
{ \p!UY3'
y_PA9#v7
#N{]
} A%w9Da?B
fECV\Z
//线程睡眠 j26i+Z
public static void sleep(int nSecond) +!).'
{ \((MoQ9Qk
try{ Iv6 lE:)
Thread.sleep(nSecond); (Cr
} ;<~f-D,
catch(Exception e) N^ +q^iW
{ ._+cvXy
e.printStackTrace (); t{;2$z 0
} nDi^s{
} [^!SkQ
S5>s&
//日志 !~ o%KQt
public static void log(String sMsg) [$3+5K#
{ 2V~E <K-
System.err.println(sMsg); UfW=/T
} ]9!y3"..W{
SIK:0>yK"
0E\#!L
public static void log(int sMsg) 7_~sa{1R.
{ D:`Q\za
System.err.println(sMsg); Mi]^wCF
} $(}rTm
} w_"d&eYdg0
`2>p#`
f )Lcs
/* o Mz{j:
**TestMethod.java Ry95a%&/s
*/ XPhP1 ^>\
package NetFox; Dgz,Uad8f
8Z!%rS
,ye}p1M
public class TestMethod { )\])?q61
{@X>!]
<F^9ML+'
public TestMethod() $9%F1:u
{ ///xx/weblogic60b2_win.exe ByqVNz0L
try{ QC'Ru'8S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); izSX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~vTwuc\(H
SiteFileFetch fileFetch = new SiteFileFetch(bean); eEXNEgbn
fileFetch.start(); cB&_':F
} -9vNV:c
catch(Exception e){e.printStackTrace ();} U\%r33L )
RUY7Y?
O=__w *<
} ")KqPD6k
V u")%(ix
)\yK61aX
public static void main(String[] args) 6UCF w>
{ 0"7+;(\1Rk
new TestMethod(); 2hV -h
} s AFn.W
} :uo)-9_
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