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)); %@Ty,d:;=
} *b0f)y3RV
for(int i=0;i<nEndPos.length-1;i++) P*;zDQy
{ 0if~qGm=!
nEndPos = nStartPos[i+1]; PXYo@^ 3
} 9fL48f$
nEndPos[nEndPos.length-1] = nFileLength; w oSI 2i
} RI%ZT
} _mw(~r8R
%,M(-G5j;
OjiQBsgnj
//启动子线程 \!4sd2Yi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PjkJsH
for(int i=0;i<nStartPos.length;i++) c}>p"
{ "Q~-C|x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z2lEHa?w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #E( n
nStartPos,nEndPos,i); \WeGO.i-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?0VLx,kp
fileSplitterFetch.start(); BK1Aq3*)
} ES#K'Lf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }TCOm_Y/qL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SrVJ Q~:>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `<L6Q2Y>j
nEndPos = " + nFileLength); { +%S{=j
// fileSplitterFetch[nPos.length-1].start(); ~^Y(f'{
U\A*${
{s=$.Kg
//等待子线程结束 Rg6e7JVu
//int count = 0; 'nM)=
//是否结束while循环 ei8OLcw:x
boolean breakWhile = false; 85fBKpEe
wb }W;C@
x-_!I>l&
while(!bStop) kOGpe'bV
{ i+V4_`
write_nPos(); vO)nqtw
Utility.sleep(500); 2ajQ*aNq
breakWhile = true; Y`u.P(7#
q)uq?sZe
y8KJoVPiM
for(int i=0;i<nStartPos.length;i++) C9q`x2
{ !.'@3-w]
if(!fileSplitterFetch.bDownOver) S/ Y1NH
{ hD>O LoO
breakWhile = false; ~ 0x9`~
break; b:S#Sz$
} `~"l a>}
} &zF1&J58z
if(breakWhile) 7 C5m#e3
break; ~pqp`
Z;_WU
oh5fNx
//count++; \DE`tkV8
//if(count>4) j_?U6$xi
// siteStop(); k.DDfuKN
} uSs~P%@6|
QMzBx*g(
c4R6E~S
System.err.println("文件下载结束！"); ^AUmIyf_
} }cll? 2
catch(Exception e){e.printStackTrace ();} PF1m :Iz`d
} zX!zG<<K
A}b<Lg
otXB:a
//获得文件长度 P(W7,GD,k
public long getFileSize() /R< Q~G|\
{ xOjCF&W
int nFileLength = -1; =J,aBp
try{ cvbv\G'aT
URL url = new URL(siteInfoBean.getSSiteURL()); $b#"Rv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l|fOi A*K
httpConnection.setRequestProperty("User-Agent","NetFox"); /._wXH
~<pGiW'w5
MS6^= ["
int responseCode=httpConnection.getResponseCode(); {O6f1LuH
if(responseCode>=400) ?<Dinq
{ Rp)82- .
processErrorCode(responseCode); L!-@dz
return -2; //-2 represent access is error 4b8!LzKS
} ,2)LH'Xx
E#_TX3B
)#r]x1[Kn
String sHeader; m?_S&/+*
o_<o8!]l"
;b$(T5
for(int i=1;;i++) aIk%$Mat
{ & h9ji[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n-dO |3,
//Utility.log(in.readLine()); //W<\
sHeader=httpConnection.getHeaderFieldKey(i); (i7]N[
if(sHeader!=null) ,|b<as@X
{ #5T+P8
if(sHeader.equals("Content-Length")) L^VG?J
{ <!&&Qd-d6H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); a Kb2:1EQ
break; A1p;Ye>o~
} P}H7WH
} NrTQ}_3)
else "7RQrz
break; VuFH >8n
} Fk>/
} K.] *:fd
catch(IOException e){e.printStackTrace ();} z@$7T:H>
catch(Exception e){e.printStackTrace ();} 7vV3"uns
i 4eb\j
>(u=/pp=:
Utility.log(nFileLength); A%u-6"
S 1|[}nYP
<?,o {
return nFileLength; 7,_N9Q]rB
} AMvM H
TC3xrE:U<m
mz[rB|v"/7
//保存下载信息（文件指针位置） w/N.#s^
private void write_nPos() G;FY2;adK
{ q?&vV`PG5
try{ -.1x!~.jX
output = new DataOutputStream(new FileOutputStream(tmpFile)); (eN\s98)/
output.writeInt(nStartPos.length); 0,nDyTS^
for(int i=0;i<nStartPos.length;i++) ]xA;*b;|h
{ 5>q|c`&}E
// output.writeLong(nPos); u%#bu^4"
output.writeLong(fileSplitterFetch.nStartPos); Z*nC ;5Kd
output.writeLong(fileSplitterFetch.nEndPos); ;]MHU/
} $r9Sn
output.close(); H(!)]dO
} ,~gY'Ql
catch(IOException e){e.printStackTrace ();} o8RagSIo8
catch(Exception e){e.printStackTrace ();} '>Y"s|
} vj^vzFbK
~jmHzFkQ
ld4QhZia
//读取保存的下载信息（文件指针位置） I1 j-Q8
private void read_nPos() Q! ]
{ d> `9!)
try{ ?I`']|I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kh 17
int nCount = input.readInt(); ~DVAk|fc
nStartPos = new long[nCount]; g%#" 5Kr
nEndPos = new long[nCount]; >tqLwC."'
for(int i=0;i<nStartPos.length;i++) 2IqsBK`
{ w:Tz&$&Y$
nStartPos = input.readLong(); WtFv"$V
nEndPos = input.readLong(); $Dd IY}
} s<xD$K~rM
input.close(); Wj/.rG&tE
} $k V^[
catch(IOException e){e.printStackTrace ();} }f<.07
catch(Exception e){e.printStackTrace ();} ykxjT@[
} ]0zXpMNI
?z171X0
GNqw]@'Yf
private void processErrorCode(int nErrorCode) ~9p*zC3M
{ 'AE)&56
System.err.println("Error Code : " + nErrorCode); %:N6#;l M
} vN-#Ej. u
Zk)]=<H
MSoLx' <
//停止文件下载 I7nt<l!
public void siteStop() \D<rT)Tl
{ B[!wo
bStop = true; ATv.3cy
for(int i=0;i<nStartPos.length;i++) L=Fm:O'#2
fileSplitterFetch.splitterStop(); # h]m8
h2zuPgz,
,g#=pdX;
} Z+=WgEu1
} jnYFA[Ab
//负责部分文件的抓取 ^vLHs=<
**FileSplitterFetch.java q[nX<tO
*/ ]ZelB,7q
package NetFox; _0 USe
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ce/Rzid
import java.io.*; !%_Z>a
import java.net.*; xXE/pIXw
vX]\Jqy
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public class FileSplitterFetch extends Thread { &eG,CIT
> F&Wuf
D:U:( pg
String sURL; //File URL 4T`u?T]
long nStartPos; //File Snippet Start Position d Ayof=
long nEndPos; //File Snippet End Position 3205gI,
int nThreadID; //Thread's ID \Q|1I
boolean bDownOver = false; //Downing is over G@oY2sM"
boolean bStop = false; //Stop identical 3aQWzEnh
FileAccessI fileAccessI = null; //File Access interface @>_`g=
h)"PPI
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j08}5Eo
{ G%
this.sURL = sURL; En&ESWN
this.nStartPos = nStart; =LL5E}xP
this.nEndPos = nEnd; &7!&]kA+
nThreadID = id; # nwEF QA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G,e>dp_cPu
} lplEQ]J|
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r ioNP(
public void run() .dt7b4.kd
{ 7JD jJQy
while(nStartPos < nEndPos && !bStop) [nJ),9$z_
{ z/)HJo2#
(GJ)FWen0"
fD
try{ YQvN;W
URL url = new URL(sURL); $*V:;-H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <->Nex
httpConnection.setRequestProperty("User-Agent","NetFox"); ~&4Hc%*IB
String sProperty = "bytes="+nStartPos+"-"; bX:Y5o49
httpConnection.setRequestProperty("RANGE",sProperty); lOt3^`
Utility.log(sProperty); r9sW:cM:e
)d!,,o
V~tq _
InputStream input = httpConnection.getInputStream(); 1hw1AJ}(F
//logResponseHead(httpConnection); F=U3o=-:
,o& &d.
2--"@@
byte[] b = new byte[1024]; 3k py3z[%
int nRead; WLd{+y5#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Fd":\7p
{ '3O@Nxof4
nStartPos += fileAccessI.write(b,0,nRead); Mp^%.m
//if(nThreadID == 1) d&4]?8}=.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w7cciD|
} +VkhM;'"C
r5h}o)J
$NC1>83
Utility.log("Thread " + nThreadID + " is over!"); X}Bo[YoY$
bDownOver = true; &u( eu'Q3
//nPos = fileAccessI.write (b,0,nRead); @cA`del
} d!5C$C/x
catch(Exception e){e.printStackTrace ();} x+x6F
} +!6aB|-
} l69&-Nyg
ml<X92Y
,4zwd@&O
//打印回应的头信息 3`S|I_$(T"
public void logResponseHead(HttpURLConnection con) ?F1NZA[%t
{ >j5) MF{"
for(int i=1;;i++) i\lur ET
{ I *YO
String header=con.getHeaderFieldKey(i); 4n @}X-)
if(header!=null) zV_U/]y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'VcZ_m:
Utility.log(header+" : "+con.getHeaderField(header)); [,Q(~Qb
else !qsk;Vk7Z
break; Z{s&myd
} Y u\<
} la:i!qAH
D7H,49#1Q
@d]I3?`
public void splitterStop() sgp5b$2T.
{ / PDe<p
bStop = true; S C7Tp4
} rVgz+'rFD[
aT1T.3 a
9otA5I^v
} wegu1Ny
~G|un}g=
SN+B8*!
/* qP{S!Z(
**FileAccess.java _xT=AF9~o
*//文件访问(定位，写) S*-n%D0q5
package NetFox; k~Qb"6n2
import java.io.*; Dnn$-W|NC
>Y=HP&A<
eSo/1D
public class FileAccessI implements Serializable{ hfT HP
~L$B]\/A5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _i{$5JJ+K2
RandomAccessFile oSavedFile; y`O !,kW
long nPos; N=FU>qbz
p?(w!O
Y^80@MJ
public FileAccessI() throws IOException hT4u;3xE
{ gdkl,z3N3
this("",0); ^Yz.,!B[
} [~03Z[_"/
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"S#4
public FileAccessI(String sName,long nPos) throws IOException ru[W?O"
{ r2A%.bL#
oSavedFile = new RandomAccessFile(sName,"rw"); ,CqJ((
this.nPos = nPos; qOy3D~
oSavedFile.seek(nPos); ^*.S7.;2o
} c&r8q]u
1-[~}
gM_z`H5[!
public synchronized int write(byte[] b,int nStart,int nLen) R\k= CoJJ
{ pwo5Ij,~q
int n = -1; L".Qf|b*
try{ td!WgL,m
oSavedFile.write(b,nStart,nLen); V ;Kzh$^rk
n = nLen; ?mKj+Bk2
} *#+e_)d
catch(IOException e) B;xw @:H
{ <tkxE!xF`J
e.printStackTrace (); AffVah2o:
} BzBij^h
%\6ns
P'f0KZL;
return n; EWuuNf
} xxxM
0sq?;~U
3Mw\}q
} ^.bYLF
Zwy8SD'L
Sh'>5z2
/* rmpx8CY"
**SiteInfoBean.java z d 9Gi5&
*/ _~!*|<A_
package NetFox; l{oAqTN
jR8~EI+
cx%[hM09
public class SiteInfoBean { |O0=Q,<m
*:t]|$;E\
i!8 o(!I
private String sSiteURL; //Site's URL o('W2Bs-o
private String sFilePath; //Saved File's Path <hlH@[7!
private String sFileName; //Saved File's Name Z-(#}(HD
private int nSplitter; //Count of Splited Downloading File ,Q|[Yr
]~S,K}T
}p-<+sFo
public SiteInfoBean() mXZOkx{
{//nSplitter的缺省值为5 @Dc?fyY*o<
//default value of nSplitter is 5 +C3IP
this("","","",5); VB6EM|bphl
} `:WVp~fn
n{vp&
xb#M{EE-.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 48X;'b,h
{ q~*3Bk~
sSiteURL= sURL; Mf0!-bu
sFilePath = sPath; H':dLR
sFileName = sName; TAz#e
this.nSplitter = nSpiltter; 'VA\dpa{J
GE4d=;5
-$Bom
} qc^u%
{2kw*^,l
.#n1p:}[
public String getSSiteURL() @91Q=S
{ ~doOt
return sSiteURL; # Sfz^
} BNU]NcA#*,
'Y23U7 n0B
hpJ[VKe
public void setSSiteURL(String value) MGn:Gj"d
{ O+Z[bis`
sSiteURL = value; h%e}4U@X
} yjCY2T E
PMr {BS
S-^y;#=
public String getSFilePath() q^}QwJw
{ |RT#ZMJek
return sFilePath; 0:-i
} )W^Wqa8mG|
,aI 6P-
#;. tVo I
public void setSFilePath(String value) uS :3Yo
{ ]p3hq1u3&
sFilePath = value; _2{i}L
} <d$kGCz
#BK\cIr
6hKavzSi
public String getSFileName() ;6aTt2BQ
{ "kyy>H9)
return sFileName; 75vd ]45as
} hg7`jE&2
Qxj &IX
u?[P@_i<
public void setSFileName(String value) n y6-_mA]
{ *au&ODa
sFileName = value; =8OPjcX.V
} 7NG^X"N{Ul
)mO|1IDTN
b{H&%Jx)
public int getNSplitter() 6L@g]f|Y@
{ =!3G,qV
return nSplitter; GCul6,w
} =]x FHw8A
<rc3&qmd
P\bW kp0
public void setNSplitter(int nCount) <~# ZtD$G
{ `+]9+:tS
nSplitter = nCount; !?B9 0(
} NC::;e
} MNip;S_j
i}Ea>bi{N
%)_R>.>
/* Pz3jc|Ga
**Utility.java :,<e
*/ V/i&8UMw
package NetFox; -)@DH;[tb
|x3&#(Tf
aE.T%xR
public class Utility { !!f)w!wW
7]a6dMh
R:YX{Tq
public Utility() !]qwRB$5
{ CD1}.h
Ty\&ARjb 8
'LIJpk3J
} hBDPz1<
/yn1MW[.
//线程睡眠 y6Xfddd61
public static void sleep(int nSecond) 1vQf=t%lw
{ Mvoi
try{ sAS\-c'6
Thread.sleep(nSecond); \>nPg5OT
} l<)(iU
catch(Exception e) ]od]S8$5
{ `/ix[:}m^
e.printStackTrace (); Fs_V3i3|L
} J!%Yy\G
} zllY$V&<!
l){l*~5zl2
//日志 7~TE=t
public static void log(String sMsg) t6_6Bl:
{ 1g{`1[.QO
System.err.println(sMsg); 0rY<CV;fZ
} 9ZUG~d7_
JE,R[` &
E,E:WuB
public static void log(int sMsg) : :8UVLX
{ Hx2.2A^
System.err.println(sMsg); C/%umazP9
} nab:y(]$/
} jy{T=Nb
x, a[ p\1
95^w" [}4Q
/* h";G vjy
**TestMethod.java ("o<D{A
*/ Jis{k$4
package NetFox; YMLo~j4J
1eI>Yy>}
*\m 53mb
public class TestMethod { AS`0.RC-
Hk8:7"4Q
F6Zl#eL
public TestMethod() KbVV[ *
{ ///xx/weblogic60b2_win.exe 7qA);N
try{ =K{$?%"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); YFOK%7K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K$(&Qx}
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3WS`,}
fileFetch.start(); vp &jSfQ^
} Fgxh?Wd9
catch(Exception e){e.printStackTrace ();} t`+x5*gW
gE(QVbh(
2#C!40j&\
} QsI#Ae,O#;
d6,%P6
o\h[K<^>)
public static void main(String[] args) '(Uyju=
{ c`mJrS:
new TestMethod(); b_cnVlN[
} J7t5B}}
} #*#4vMk<
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