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)); yn@wce
} A.7lo
for(int i=0;i<nEndPos.length-1;i++) P0_Ymn=&
{ _-#o[>2[
nEndPos = nStartPos[i+1]; !2&)6SL/
} Khv}q.)F
nEndPos[nEndPos.length-1] = nFileLength; ME!P{ _/
} dblf,x
} ^jb;4nf
ndT_;==
!a\HdQ
//启动子线程 3}3b@:<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;gu4~LQw
for(int i=0;i<nStartPos.length;i++) |9.J?YP8 (
{ _I3"35a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /pU`-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B<Cg_C
nStartPos,nEndPos,i); ;o;ak.dTt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [euR<i*I#
fileSplitterFetch.start(); qe?Ns+j<d
} I`jG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iqB%sIP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2!CL8hG5:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @}waZ?'
nEndPos = " + nFileLength); +>2.O2)%q
// fileSplitterFetch[nPos.length-1].start(); </5
wL]#]DiE
snu?+*6
//等待子线程结束 ,afO\oe>MG
//int count = 0; @ZJ}lED3
//是否结束while循环 |=~mRqG
boolean breakWhile = false; JV4fL~
u0)9IZxc
vr?u=_%Z
while(!bStop) Pk(%=P,
{ 9&Y|,&W
write_nPos(); E;'{qp
Utility.sleep(500); *}Gys/\!S
breakWhile = true; rK}sQ4z=
kD1Nq~h2
lt]&o0>
for(int i=0;i<nStartPos.length;i++) r}Gku0Hu_E
{ 5&_")k3$*
if(!fileSplitterFetch.bDownOver) #cW:04
{ xX{Zh;M&[
breakWhile = false; ]mNsG0r6
break; Oi$1maxT
} m!^$_d\%~
} =(P$P
if(breakWhile) v_v>gPl,
break; & @_PY
X&rsWk
<4@8T7
//count++; m#O; 1/P
//if(count>4) (]&B'1b
// siteStop(); "cjD-42
} " ;T a8
HFFrS%
QuI!`/N)z
System.err.println("文件下载结束！"); ;.=0""-IF
} jA~omX2A
catch(Exception e){e.printStackTrace ();} SdMLO6-
} >\J<`
1P'L<z
8I#^qr5
//获得文件长度 Y,,Z47% E
public long getFileSize() O7.eq524
{ _/.VXW
int nFileLength = -1; +7 j/.R
try{ Lc]hwMGR*
URL url = new URL(siteInfoBean.getSSiteURL()); KjF8T7%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %gSmOW2.c^
httpConnection.setRequestProperty("User-Agent","NetFox"); !Z{7X ^
Vu4LC&q
\`2EfYJ{
int responseCode=httpConnection.getResponseCode(); U#PgkP[4
if(responseCode>=400) Fe$o*r,
{ ZJhI|wRwD
processErrorCode(responseCode); 9PG{>W$M
return -2; //-2 represent access is error gVJh@]8)
} "WXUz
3i4m!g5Z?
>f-RzQ k
String sHeader; Ad3TD L?
$3ZQ|X[|+
]]}iSw'
for(int i=1;;i++) Iue=\qUK^
{ 2,Z@<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K$:btWSm
//Utility.log(in.readLine()); >){}nlQf
sHeader=httpConnection.getHeaderFieldKey(i); v6! `H
if(sHeader!=null) -!M>;M@
{ Q.V@Sawe5
if(sHeader.equals("Content-Length")) nG?Z* n
{ ? IlT[yMw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H<g8u{ $
break; |DVFi2
} o"P)(;
} K)Z~ iBRM
else At[SkG}b
break; 9oP
} "qZTgCOY2
} FLkZZ\
catch(IOException e){e.printStackTrace ();} )?l7I*
catch(Exception e){e.printStackTrace ();} Qn-nO_JL
3G^A^]h
i\.(6hf+
Utility.log(nFileLength); 8-kR {9r
$`vXI%|.
m@L>6;*
return nFileLength; If'N0^'W
} 1E4`&?
GN5*
%=s2>vv9
//保存下载信息（文件指针位置） E6T=lwOZ
private void write_nPos() 2pSp(@N3
{ ajM\\a?
try{ ]ERAt^$0
output = new DataOutputStream(new FileOutputStream(tmpFile)); V@gG x
output.writeInt(nStartPos.length); =0;njL(7;
for(int i=0;i<nStartPos.length;i++) zc,X5R1
{ <RH%FhT
// output.writeLong(nPos); ka(3ONbG
output.writeLong(fileSplitterFetch.nStartPos); LRS,bl3}/
output.writeLong(fileSplitterFetch.nEndPos); rF{,]U9`
} auY?Cj'"fs
output.close(); x1Gc|K/-
} Y q|OX<i`K
catch(IOException e){e.printStackTrace ();} Hxc>?
catch(Exception e){e.printStackTrace ();} `m"K_\w=/
} wk^$DM/KJ)
ggfCfn
c3<H272\
//读取保存的下载信息（文件指针位置） ExL7 ]3r
private void read_nPos() [IHG9Xg
{ >*+n`"6
try{ ~Xr[d07bC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OP_\V8=
int nCount = input.readInt(); SF ^$p$mC
nStartPos = new long[nCount]; @.G;dL.f{
nEndPos = new long[nCount]; [3tU0BU"
for(int i=0;i<nStartPos.length;i++) 3fYfj
{ pk;S"cnk
nStartPos = input.readLong(); or7l}X
nEndPos = input.readLong(); c@j3L23B
} .~^A!t
input.close(); ;{e'q?Y
} tm_\(
catch(IOException e){e.printStackTrace ();} ir|L@Jj,
catch(Exception e){e.printStackTrace ();} 4Y G\<Zf
} {8%KO1xB
HuN_$aP
4>B=k
private void processErrorCode(int nErrorCode) (Bpn9}F-V.
{ DD>n-8M@>
System.err.println("Error Code : " + nErrorCode); .H&XPW
} sYk#XNH
!9V; 8g
VPVg\K{
//停止文件下载 7kMO);pO
public void siteStop() NKVLd_f k
{ X@A8~kj1
bStop = true; j~9![s!
for(int i=0;i<nStartPos.length;i++) V9>$M=
fileSplitterFetch.splitterStop(); VjeF3pmBa
3?!c<^"e
]&='E.f
} e_S,N0
} (8NE'd8
//负责部分文件的抓取 <Y;w I#C
**FileSplitterFetch.java kD((1v*D$
*/ 7Fzr\&
package NetFox; 6J-=6t|
\t=#MzjR
.^ba*qb`{
import java.io.*; 85A7YraL
import java.net.*; c;#gvE
1k$5'^]^9]
g<8Oezi 65
public class FileSplitterFetch extends Thread { 2';{o=TXV
>I+p;V$@
]x'd0GH"]
String sURL; //File URL Jr(Z Ym'
long nStartPos; //File Snippet Start Position @v\8+0
long nEndPos; //File Snippet End Position _ZK*p+u%
int nThreadID; //Thread's ID I%z,s{9p
boolean bDownOver = false; //Downing is over $B]_^
boolean bStop = false; //Stop identical D|vck1C5,
FileAccessI fileAccessI = null; //File Access interface .[?2_e#9%
I&% Z*H
^i@0P}K<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eK\i={va
{ uj)fah?Wg
this.sURL = sURL; idjk uB(6
this.nStartPos = nStart; v++&%
this.nEndPos = nEnd; {~'Iu8TvZ
nThreadID = id; O`9vEovjs
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1V,DcolRY
} sP>-k7K.
v*OT[l7
))7CqN
public void run() rWN%j)#+
{ Vw&#Lo
while(nStartPos < nEndPos && !bStop) )3 '8T>^<K
{ -O $!sFmY
*3fhVl=8^*
CX]L'
try{ gL7rX aj
URL url = new URL(sURL); 7oCY@>(f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z)u\(W*\iA
httpConnection.setRequestProperty("User-Agent","NetFox"); 8rLhOA
String sProperty = "bytes="+nStartPos+"-"; /%bnG(4
httpConnection.setRequestProperty("RANGE",sProperty); B~YOU3
Utility.log(sProperty); /3;]e3x
!~xlze
/.t1Ow
InputStream input = httpConnection.getInputStream(); kJCeQK:W
//logResponseHead(httpConnection); {=MRJg!U
TALiH'w6|e
>h$Q%w{V
byte[] b = new byte[1024]; -6e^`c6{
int nRead; D]WrPWL8v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e0]%ko"
{ j=u) z7J
nStartPos += fileAccessI.write(b,0,nRead); L=I;0Ip9y
//if(nThreadID == 1) 2~yj =D27Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P<LmCYm
} CFu^i|7o
$qR@;=
}>b@=5O
Utility.log("Thread " + nThreadID + " is over!"); NE|Q0g
bDownOver = true; }V 4u`=
//nPos = fileAccessI.write (b,0,nRead); 5>VX]nE3!
} Z4sS;k]}
catch(Exception e){e.printStackTrace ();} MIqH%W.ru
} okO\A^F
} ]\/"-Y#4Q
3sl6$NKo
9&Z+K'$=
//打印回应的头信息 xiqeKoAD
public void logResponseHead(HttpURLConnection con) Tsdgg?#
{ Dnd
for(int i=1;;i++) FyNm1QNy^
{ D&OskM60
String header=con.getHeaderFieldKey(i); ({cWb:+r
if(header!=null) m!3D5z]n9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4Zn [F^p
Utility.log(header+" : "+con.getHeaderField(header)); #@E:|^$1y
else 00yWk_w
break; ;"8BbF.
} ^AoX|R[1%
} eZ 7Atuv
#9{2aRCJ
b&RsxW7
public void splitterStop() 9!ARr@ ;
{ O.{
bStop = true; ?[)V
} 7/)0{B4U'
}-Jo9dNs
B)dG:~
} XQ8q)B=
*aGJ$ P0
C(M?$s`
/* 4P#4RB
**FileAccess.java C* 0ZF
*//文件访问(定位，写) }%D${.R]
package NetFox; {Ia$!q)
import java.io.*; .fS{j$
{YwdhwJP
(U\D7ItMG
public class FileAccessI implements Serializable{ moZeP#Q%
:`uu[^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %\~U>3Q
RandomAccessFile oSavedFile; . "7-f]!
long nPos; G9@5 !-
^~dC&!D
3Z7gPU!H=
public FileAccessI() throws IOException 3#eAXIW[
{ -vc ,O77z"
this("",0); +x<OyjY5?]
} L^K,YlNBR
CY$ 1;/
KDj/S-S
public FileAccessI(String sName,long nPos) throws IOException 86a,J3C[
{ hDc2T
oSavedFile = new RandomAccessFile(sName,"rw"); "Jdi>{o8
this.nPos = nPos; 8/;@4^Ux
oSavedFile.seek(nPos); hBhbcWD,ka
} *w}r:04F
$'yWg_(
vI:_bkii
public synchronized int write(byte[] b,int nStart,int nLen) !>/J]/4>
{ i(V
int n = -1; q_[`PYT
try{ s+E4AG1r
oSavedFile.write(b,nStart,nLen); ubc k{\.
n = nLen; 4M+f#b1
} sejT] rJ
catch(IOException e) 6P)DM
{ <&bBE"U4
e.printStackTrace (); D}UgC\u
} -#R63f&
2-@t,T
'$5d6?BC`3
return n; }g:'K
} ?[%.4i;-h
@q{.
\tCK7sBn
} RJ{J~-q{
yV31OBC:
_Ih"*~ r/&
/* `'gcF});
**SiteInfoBean.java '{cFr
*/ 6rO^ p
package NetFox; `G=+qti
LLoV]~dvUu
jc@= b:r=
public class SiteInfoBean { ;ULw-&]P
1[-`*Ph
@g*[}`8]y
private String sSiteURL; //Site's URL q;_?e_
private String sFilePath; //Saved File's Path 'Zqt~5=5
private String sFileName; //Saved File's Name 3Q2NiYg3
private int nSplitter; //Count of Splited Downloading File @moaa}1
Ak$9\Sl
/UaQ2h\
public SiteInfoBean() $-<yX<.
{//nSplitter的缺省值为5 \x5>H:\Y
//default value of nSplitter is 5 ZT`" {#L
this("","","",5); MJa`4[/
} "#iO{uMWb
TJB4N$-}A
eKU4"XTk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Oi{J}2U
{ K7/&~;ZwT
sSiteURL= sURL; P2U4,?_e
sFilePath = sPath; ;Rm';IW$
sFileName = sName; v "[<pFj^
this.nSplitter = nSpiltter; aJc>"#+ o
:_+U[k(#
K9K.mGYc
} XXQC`%-]<i
' -aLBAxy
4#I=n~8a
public String getSSiteURL() {}=5uU2Tu
{ ^9YS dFH/
return sSiteURL; ^PMA"!n8
} 8v)HTD/C
0BAZWm
"j.Q*Hazg
public void setSSiteURL(String value) j J54<.D
{ )0Vj\>
sSiteURL = value; c)q=il7ef
} -x?|[ +%
vq@"y%C4
"u{ymJ]t
public String getSFilePath() E;"VI2F
{ -W:@3\{
return sFilePath; 5r;)Ppo
} dkg+_V!
@9k3}x K
h,K&R8S
public void setSFilePath(String value) pTJ_DH
{ )5Cqyp~P
sFilePath = value; >z,Y%A
} R1.Yx?
ZY;g)`E1
")NQwT}
public String getSFileName() KCqz]
{ 7JY9#+?p>
return sFileName; :JXcs39
} 0|4R8Dh*-
j9cB<atL
$0]5b{i]
public void setSFileName(String value) 9N|JI3*41
{ 9yLPh/!Ob
sFileName = value; s,D GFK
} H/*i-%]v+(
")fgQ3XZ
K5(T7S
public int getNSplitter() 2"o<>d
{ [u-=<hnoa
return nSplitter; Q1H.2JXr
} % 5BSXAc
C3 m_sv#e
Gr3 q
public void setNSplitter(int nCount) ADMeOdgca
{ (8em5
nSplitter = nCount; 9AD0|,g
} .0|_J|{
} C?\HB#41
9g$fFO
g](&H$g
/* 9 I&[6}
**Utility.java wOH 3[SKo
*/ /&!o]fU1C
package NetFox; TNcMrbWA
A\ tBmL_s
ZV07;`I
public class Utility { za8+=?
S:c lyx
vTp,j-^
public Utility() 0BOL0<Wq
{ tV7{j'If
cr^R9dv
"7?xaGh8
} 1+tPd7U
^SwU]e
//线程睡眠 ikPr>
public static void sleep(int nSecond) J/[PA[Rf
{ UG<<.1JL
try{ (k%r_O6
Thread.sleep(nSecond); zK*i:(>B
} 8#Y_]Z?)
catch(Exception e) d~b@F&mf
{ GVdJ&d\x
e.printStackTrace (); 86o'3G9@
} mNX0BZ
} 1DF8-|+
\<b42\a}
//日志 dBW4%Zh
public static void log(String sMsg) 4_4|2L3
{ G2J4N2hu
System.err.println(sMsg); F+V[`w*k
} "2I{T
#Vm)wH3
R7x*/?
public static void log(int sMsg) _cbXzSYq&
{ D6EqJ,~
System.err.println(sMsg); JJP!9<
} qmnW
} 57$/Dn
;ZZmX]kz,M
<XnxAA
/* 6%T_;"hb
**TestMethod.java -"xC\R
*/ -}Rh+n`
package NetFox; 'gk^NAG2^E
N&u(9Fxn
/IC]}0kkp
public class TestMethod { m9Dg%\B
e4cWi
0#F<JsO|u
public TestMethod() "04:1J`
{ ///xx/weblogic60b2_win.exe Aac7km
try{ 6x8lnXtA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ude)$PAe%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :NWrbfz
SiteFileFetch fileFetch = new SiteFileFetch(bean); 83{v_M
fileFetch.start(); @OC*:?!4
} c$)!02
catch(Exception e){e.printStackTrace ();} zM'2opiUY
gac/%_-HH7
'Ub\8<HfJU
} ]tEH`Kl
o(xt%'L`t
vu/P"?F
public static void main(String[] args) LeMo")dk\
{ jL~. =QD
new TestMethod(); 8;Df/%
} mzTM&@
} 0a)LZp|
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