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)); \(_FGa4j
} <Vp7G%"'W
for(int i=0;i<nEndPos.length-1;i++) jqHg'Fq
{ X#mm Z;P
nEndPos = nStartPos[i+1]; Sc "J5^
} H`4H(KWm
nEndPos[nEndPos.length-1] = nFileLength; Xz5 aTJ&
} gP.Q_/V
} uV<I!jyI
2U,O e9
gkS#=bv9e@
//启动子线程 | ]`gps
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r@+IDW.=9
for(int i=0;i<nStartPos.length;i++) uAT01ZEm
{ ,)A^3Q*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fz7(Kuc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [X:mmM0gd
nStartPos,nEndPos,i); FKflN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yn<z!z%mz
fileSplitterFetch.start(); H<|I&nV
} P8.tl"q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iZ+\vO?|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "|pNS)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UM%[UyYQ
nEndPos = " + nFileLength); ,-Fhb~u
// fileSplitterFetch[nPos.length-1].start(); i> Ssp
#=R)s0j"
<Ft6d
//等待子线程结束 ^GdU$%aa
//int count = 0; ann!"s_
//是否结束while循环 y'4H8M2?
boolean breakWhile = false; ^\ &:'$f+8
]H7_bix
j.4oYxK!s/
while(!bStop) cA ;'~[
{ W?{:HV
write_nPos(); pRmnS;*z&
Utility.sleep(500); Lys4l$J]
breakWhile = true; Kg&{ ?&
y|b|_eE?{
HGmgQ>q@M$
for(int i=0;i<nStartPos.length;i++) F?'=iY<h
{ zmy94Y5PE
if(!fileSplitterFetch.bDownOver) M*| y&XBe
{ L f[>U
breakWhile = false; sChMIbq!Av
break; l(9$s4R
} cH6ie?KvAo
} jJl6H~ "q
if(breakWhile) 9BB<. p
break; hi,!
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,s0E]](
//count++; Fa^5.p
//if(count>4) i](,s.
// siteStop(); cs`/^2Vf"#
} Y."ujo#bB
i7 `dY{p7
R3F>"(P@tS
System.err.println("文件下载结束！"); j~V@0z.
} w.J[3m/
catch(Exception e){e.printStackTrace ();} (utm+*V,
} hu\HK81m
bJe*J\){
<5/r
//获得文件长度 h{.KPK\
public long getFileSize() OlhfBu)~
{ PRl\W:_t
int nFileLength = -1; +O3zeL
try{ joDnjz=
URL url = new URL(siteInfoBean.getSSiteURL()); 6cSMKbgZJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @lAOi1m,,
httpConnection.setRequestProperty("User-Agent","NetFox"); b].:2
H[V^wyi'z
v vlfL*f
int responseCode=httpConnection.getResponseCode(); {6)fZpd)@
if(responseCode>=400) S5d:?^PGg
{ RH ow%2D
processErrorCode(responseCode); )H$Ik)/N
return -2; //-2 represent access is error sj2v*tFb
} <Hhl=6op
@``kt*+K+
y4)M,+O5
String sHeader; />q=qkdq0
aGNVqS%y
_~_04p
for(int i=1;;i++) NKLGbH
{ dra'1E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ];6c/#2x
//Utility.log(in.readLine()); rwFR5
sHeader=httpConnection.getHeaderFieldKey(i); wRb%-s
if(sHeader!=null) 7CUu:6%
{ *103
if(sHeader.equals("Content-Length")) zc]F
{ O/gok+K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~j3B'
break; Yqmx]7Y4
} Vj4 if@Z
} $/],QD_;"
else wQ!~c2a<8
break; ~wDmt
} |K'{R'A
} tu77Sb
catch(IOException e){e.printStackTrace ();} \8Mkb]QA
catch(Exception e){e.printStackTrace ();} E xKH%I
nFW^^v<
vX)6N#D!
Utility.log(nFileLength); MjE.pb
EG&^;uU
^j';4'
return nFileLength; l7aGo1TcIh
} 66D<Up'K
wc)[r~On(5
{b^naE
//保存下载信息（文件指针位置） [ar:zlV8
private void write_nPos() xj{X#[q):
{ "Na9Xea
try{ v6oPAqj,r
output = new DataOutputStream(new FileOutputStream(tmpFile)); riZFcVsB
output.writeInt(nStartPos.length); :tdx:
for(int i=0;i<nStartPos.length;i++) VbM5]UT/
{ ]~8bh*,=
// output.writeLong(nPos); >?'q P ]
output.writeLong(fileSplitterFetch.nStartPos); zJI/j _~W
output.writeLong(fileSplitterFetch.nEndPos); ,.]e~O4R
} WRh&4[G'
output.close(); &[*_ -
} #"ayq,GC<
catch(IOException e){e.printStackTrace ();} |/arxb&
catch(Exception e){e.printStackTrace ();} A/{pG#if]3
} 8jqt=}b
2P$lXGjh
5YC56,X
//读取保存的下载信息（文件指针位置） ce2d)FG}e
private void read_nPos() FO_nS
{ ,p1 (0i
try{ & /-@R|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .`Z{ptt>
int nCount = input.readInt(); FvG9PPd
nStartPos = new long[nCount]; "x9xJ
nEndPos = new long[nCount]; l4U& CA y
for(int i=0;i<nStartPos.length;i++) $2]1 3j
{ Ou2H~3^PL
nStartPos = input.readLong(); BGOI$,
nEndPos = input.readLong(); Rt7}e09HV
} X]cB`?vR
input.close(); Lj*FKP\{
} ol!o8M%Q
catch(IOException e){e.printStackTrace ();} KblOP{I
catch(Exception e){e.printStackTrace ();} {tOuKnnS
} J}jK_
FPaj p
-J[zJ4z#
private void processErrorCode(int nErrorCode) *^Zt5 zk
{ t8i"f L
System.err.println("Error Code : " + nErrorCode); C>v
} k%hD<_:p
E|97zc
~(aq3ngo.
//停止文件下载 ejgg.G ^
public void siteStop() &M>S$+I n
{ e7,iO#@:m
bStop = true; yel>-=Vn
for(int i=0;i<nStartPos.length;i++) CSr{MF`]e
fileSplitterFetch.splitterStop(); ,EZ&n[%Ko
%T'?7^\>
*Z{$0K
} 1"/V?ArfL
} /lr RbZ
//负责部分文件的抓取 KG>.7xVWV7
**FileSplitterFetch.java + W@r p#
*/ Z6D4VZVF
package NetFox; <g*rTqT'
=v:_N.Fh-c
Ub3,x~V
import java.io.*; Jk{>*jYk`
import java.net.*; 3BY/&'oX
q/;mxq$
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public class FileSplitterFetch extends Thread { .&sguAyG
E*(Q'p9C
*uEU9fX
String sURL; //File URL S BFhC
long nStartPos; //File Snippet Start Position `b\4h/~
long nEndPos; //File Snippet End Position ^iV@NVP
int nThreadID; //Thread's ID z7<^aS
boolean bDownOver = false; //Downing is over N->;q^
boolean bStop = false; //Stop identical 'Fonn
FileAccessI fileAccessI = null; //File Access interface %i.|bIhmm
WZm^:,
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uFok'3!g7%
{ HhqqJEp0
this.sURL = sURL; DVB:8"Bu
this.nStartPos = nStart; dtF6IdAf
this.nEndPos = nEnd; @%#(Hse
nThreadID = id; dH`a|SVW9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >,] #~d
} ]6:5<NW
>p<(CVX[
hA@X;Mh^w
public void run() @W.`'b-
{ 66|lQE&n
while(nStartPos < nEndPos && !bStop) M j5C0P(
{ ZzKn,+
vo::y"
{#[a4@B0
try{ e<p$Op
URL url = new URL(sURL); _Jp_TvP>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qHKZ5w
httpConnection.setRequestProperty("User-Agent","NetFox"); BKDWd]KEf
String sProperty = "bytes="+nStartPos+"-"; 92SB'T>
httpConnection.setRequestProperty("RANGE",sProperty); ;JZXSM-3
Utility.log(sProperty); {xH \!!"T
Q1jyetk~I
s]I],>}RU
InputStream input = httpConnection.getInputStream(); F;b|A`M
//logResponseHead(httpConnection); mdZELRu
78.sf{I
Y4{`?UM&h
byte[] b = new byte[1024]; VtKN{sSnu
int nRead; #zy%B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0)P18n"$
{ C$tSsw?A
nStartPos += fileAccessI.write(b,0,nRead); :EO}uP2
//if(nThreadID == 1) r!M2H{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TgUQD(d^
} FdSaOod8
w(G(Q>GI
ALwuw^+
Utility.log("Thread " + nThreadID + " is over!"); @i`gR%
bDownOver = true; w+MdQ@'5
//nPos = fileAccessI.write (b,0,nRead); }`MO}Pz
} o?b%L
catch(Exception e){e.printStackTrace ();} ;T_9;RU<'b
} AH7k|6ku<*
} fg1y@Dj/&
p/:5bvA
S1+#qs{5a
//打印回应的头信息 .Gv~e!a8
public void logResponseHead(HttpURLConnection con) Ym6ec|9;
{ (8*lLZ
for(int i=1;;i++) D~y]d
{ <N*>9S,}
String header=con.getHeaderFieldKey(i); asF-mf;D
if(header!=null) <G&v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _4W#6!
Utility.log(header+" : "+con.getHeaderField(header)); srSTQ\l4
else T9$U./69-L
break; <VBw1|)$@
} :1{j&$
} "/"qg
;CvGIp&y
{Q-U=me\
public void splitterStop() =aekY;/
{ [_0g^(`
bStop = true; j~{2fd<>
} i f"v4PHq
a2 SQ:d
yjr@v!o
} m3WV<Cbz
w\mF2h
N<{`n;
/* N\fT6#5B
**FileAccess.java 4sAshrUf
*//文件访问(定位，写) |")x1'M
package NetFox; `u}x:f !
import java.io.*; em]K7B=
s6D-?G*u%8
m7"f6zSo(
public class FileAccessI implements Serializable{ c`+ITNV
47RYpd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q>[% C5
RandomAccessFile oSavedFile; br;G5^j3?
long nPos; |W <:rT
/Ow?nWSt
k$c j|-<
public FileAccessI() throws IOException 'l:2R,cP
{ J4vKfxEg
this("",0); !BX62j\?
} c|R/,/
jQb D2x6(
9PJDT]
public FileAccessI(String sName,long nPos) throws IOException Z C93C7lJ
{ cOb%SC[A{
oSavedFile = new RandomAccessFile(sName,"rw"); mQs$7t[>t
this.nPos = nPos; [z~Nw#
oSavedFile.seek(nPos); zFn&~lFB
} `@M4THt
Wa(S20yF
]'Yw#YB
public synchronized int write(byte[] b,int nStart,int nLen) R u5&xIQ
{ X{ =[q|P
int n = -1; Ic}ofBK
try{ /)1-^ju
oSavedFile.write(b,nStart,nLen); TJpv"V
n = nLen; K5>:WiY
} @QG1\W'
catch(IOException e) `k&K"jA7$
{ l:eNu}{&
e.printStackTrace (); C6w{"[Wv=X
} f 99PwE(=
<<6w9wNon
cnthtv+(~
return n; 9ojhI=:
} gcxk'd
dmz3O(]$
YZl%JX
} %?hLo8
6W=:`14
"^z=r]<5
/* 2[po~}2-0
**SiteInfoBean.java _|ib@Xbin
*/ QNXxpoS#
package NetFox; 8~E)gV+v
;#9|l=
MPbPq3an
public class SiteInfoBean { (OB8vTRXP
r6JkoPMh
pXv[]v
private String sSiteURL; //Site's URL >e;STU
private String sFilePath; //Saved File's Path Jt6J'MOq
private String sFileName; //Saved File's Name bFezTl{M
private int nSplitter; //Count of Splited Downloading File 5V~p@vCx
A=UIN!
Fz&ilB
public SiteInfoBean() 0@lC5-=
{//nSplitter的缺省值为5 &|}IBu:T
//default value of nSplitter is 5 ]?(F'&
this("","","",5); io7U[#
} C-u/{CP
Ok&>[qu
HY;?z`=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %uVJLz
{ Lc<xgN+cJ
sSiteURL= sURL; /dt!J `:
sFilePath = sPath; L59oh
sFileName = sName; 2?iOB6
this.nSplitter = nSpiltter; _M[[vXH
WgJAr73 l
ZT8Ji?_n
} wp.e3l
9}cuAVI
/}`/i(k
public String getSSiteURL() Gr$*t,ZW
{ h5rP]dbhXU
return sSiteURL; VhFRh,J(T
} =veOVv[Q&/
noNF;zT
AH'4H."o/9
public void setSSiteURL(String value) A}bHfn|
{ =8p+-8M[d
sSiteURL = value; ASZ5;N4u
} KM}4^Qc
)]>G,.9C}
QYfAf3te
public String getSFilePath() ~}-p5q2
{ uuYH6bw*d
return sFilePath; #r.` V!=
} #oJbrh9J6
yF5
ht3T{4qCS
public void setSFilePath(String value) B9IXa;
{ (GEi<\16[
sFilePath = value; -*hb^MvP
} R``VQ
9LO.8Jy
} ndvV~*1
public String getSFileName() K=Z]#bm
{ 0*Km}?;0-
return sFileName; `bZU&A(`Be
} E)Qh]:<2v
%Mng8r
`)=A!x y
public void setSFileName(String value) f:[d]J|
{ w}W@M,.^
sFileName = value; &O6;nJEI
} .aismc`=
y|;8:b32
?FV7|)f
public int getNSplitter() dD^_^'i
{ j&[.2PW\
return nSplitter; u1)TG"+0
} W]D`f8r9
{nPkb5xbW
u@bOEcxK
public void setNSplitter(int nCount) VUy)4*
{ w <#*O:
nSplitter = nCount; ECS<l*i57&
} ,/?%y\:J
} "T{~,'T
adO!Gs9f?
I,<>%Z|'
/* \'??
**Utility.java Ztyv@z'/Z
*/ qBBYckS.
package NetFox; I#S~
!q-:rW?c
762o~vY6$
public class Utility { yxCMl.
n4vXm
k>:/D
public Utility() nI*(a:
{ t?9;cS4
53`9^|:
9xK4!~5V
} qX p,d
Tw`c6^%^y
//线程睡眠 oDW<e'Jm
public static void sleep(int nSecond) I(^jOgYU
{ d4p{5F7]^
try{ ^A11h6I
Thread.sleep(nSecond); u+z .J4w
} `rz`3:ZH
catch(Exception e) CRc!|?
{ xH"W}-#[
e.printStackTrace (); ?GUz?'d
} Ez/\bE
} N&I8nZ9
S2'`|uI
//日志 vJTfo#C|
public static void log(String sMsg) c#{Ywh
{ ~mXZfG/D
System.err.println(sMsg); l:zU_J6
} .#=j <&
x2j/8]'o
(o x4K{
public static void log(int sMsg) 2vqmsl?
{ %A)-m 69
System.err.println(sMsg); oh7#cFZZ0
} nr<WO~Xw~
} {?EEIfg
y:g7'+c
+ ZR(
/* ^MW\t4pZ
**TestMethod.java ,bZ"8Z"lss
*/ +CnyK(V
package NetFox; _HWHQF7
HA^jk%53
U^M@um M
public class TestMethod { E8T"{ R80
!j!Z%]7
e9~cBG|
public TestMethod() ~K5Cr
{ ///xx/weblogic60b2_win.exe r{K\(UT]!
try{ Bs+c2R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F5N>Uqr*oN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v!<PDw2'
SiteFileFetch fileFetch = new SiteFileFetch(bean); hmK8jl<6
fileFetch.start(); j+_S$T8w
} \6`v.B&v
catch(Exception e){e.printStackTrace ();} 2 ) TG
$ZQlIJZ
j~,h)C/v
} GB&Nt{
4R&*&GZ#
l `fW{lh
public static void main(String[] args) <@u0.-]
{ uz*d^gr}
new TestMethod(); 7*zB*"B'1t
} qTyg~]e9(
} KK:N [x
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