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)); xCZ_x$bk
} P|Aac,nE+^
for(int i=0;i<nEndPos.length-1;i++) _&, A
{ |!(8c>]Bo
nEndPos = nStartPos[i+1]; l`\L@~ln
} d.f0OhQ
nEndPos[nEndPos.length-1] = nFileLength; =b%f@x_U1
} Z8=?Hu
} b%lB&}uw}
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TFkG"ev
//启动子线程 PzPNvV/o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 437Wy+Q|e
for(int i=0;i<nStartPos.length;i++) +nR("Il
{ eP2Q2C8g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dSwfea_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _YX% M|#
nStartPos,nEndPos,i); 04U|Frc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }tt%J[
fileSplitterFetch.start(); 1 fcV&qHR
} l-w4E"n3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3}}/,pGSc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eY3:Nl^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]L~z9)
nEndPos = " + nFileLength); }4>u_)nt
// fileSplitterFetch[nPos.length-1].start(); ^x&x|ckR!
wwl,F=| Y
u[qy1M0
//等待子线程结束 U,2OofLM
//int count = 0; St?mq* ,
//是否结束while循环 D:9^^uVp
boolean breakWhile = false; #<Y.+:
Q%O9DCi
SLuQv?R}9
while(!bStop) KJFQ)#SW!
{ p>)1Z<D"a
write_nPos(); =+X*$'<J
Utility.sleep(500); ;,-)Z|W
breakWhile = true; |Kd6.Mx
@ fMlbJq
vE9"1M
for(int i=0;i<nStartPos.length;i++) dFg&|Lp
{ {b-C,J
if(!fileSplitterFetch.bDownOver) 6Y[&1c8
{ s>;"bzzq
breakWhile = false; DSs/D1mj&
break; <vl(a*4a
} )[hs#nKTh
} ^(&2
if(breakWhile) ^RnQX#+
break; Y<;C>Rs
>> cW0I/`
Q+f|.0r
//count++; !}c D e12
//if(count>4) HV!P]82Pa
// siteStop(); Jha*BaD~N
} U+VJiz<!
<@`K^g;W
{Q/@Y.~<
System.err.println("文件下载结束！"); d '2JMdbc
} gS(JgN
catch(Exception e){e.printStackTrace ();} _$*-?*V&
} 'tTlBf7#
Db2#QQ
+PYR
//获得文件长度 p3fVw]N
public long getFileSize() >]}VD "\
{ RCqL~7C+ k
int nFileLength = -1; 3Dc^lfn
try{ ~@@t-QY
URL url = new URL(siteInfoBean.getSSiteURL()); F@/syX;bb5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TJ>YJD
httpConnection.setRequestProperty("User-Agent","NetFox"); kk126?V]_
w32F?78]
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int responseCode=httpConnection.getResponseCode(); Nj6Np^@sH
if(responseCode>=400) p,WBF
{ Rt%Dps%
processErrorCode(responseCode); f~d=1
return -2; //-2 represent access is error _BG`!3U+
} Ge$&k
Q3lVx5G>4
>ptI!\i}
String sHeader; Q m9b:U~
UDpI @
$_ $%L0)5
for(int i=1;;i++) #euOq
{ j5Yli6r?3-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q&ed4{H<
//Utility.log(in.readLine()); EHe-wC
sHeader=httpConnection.getHeaderFieldKey(i); f].z.
if(sHeader!=null) PmId #2f
{ a[^dK-
if(sHeader.equals("Content-Length")) F`Vp
{ 0wBr_b!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;Xidv9c
break; d{!zJ+n
} J!rZskd
} -'W:P'BG
else P)TeF1~T
break; ?fs#K;w
} ^<yM0'0t
} XSZjuQ<[3
catch(IOException e){e.printStackTrace ();} :\#]uDT2=
catch(Exception e){e.printStackTrace ();} VyU!r* o
r'}#usB(
\@2sI
Utility.log(nFileLength); ,38bT#p:,r
/9y'UKl7[
!x:w2
return nFileLength; RAyR&p
} Y!E|X 3
1?+)T%"
x^F2Ywp%
//保存下载信息（文件指针位置） '.&,.E&{$
private void write_nPos() y(#F&^|
{ hYCyc-W
try{ GLl@ 6S>v
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZG)C#I1;O
output.writeInt(nStartPos.length); -JF|770i
for(int i=0;i<nStartPos.length;i++) \No22Je6d
{ a7NX~9g
// output.writeLong(nPos); K3UG6S\B
output.writeLong(fileSplitterFetch.nStartPos); Q!%CU8!`&
output.writeLong(fileSplitterFetch.nEndPos); I(WND/&
} $PbN=@
output.close(); Y@'1}=`J
} #iGz&S3iN$
catch(IOException e){e.printStackTrace ();} P3XP=G`E
catch(Exception e){e.printStackTrace ();} (Gxv?\
} D+_PyK~jc
X'bp?m
}Lwj~{
//读取保存的下载信息（文件指针位置） **YNR:#Y
private void read_nPos() 48%a${Nvvj
{ Ah2XwFg?
try{ @p2dXJeR<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =09j1:''<d
int nCount = input.readInt(); *DoEDw
nStartPos = new long[nCount]; ~h[lu^ZSi
nEndPos = new long[nCount]; {_MU0=7c\
for(int i=0;i<nStartPos.length;i++) '*p-`
{ J>Rt2K
nStartPos = input.readLong(); =Jl1D*B*
nEndPos = input.readLong(); Pq7tNM E
} TAJ9Y<
input.close(); Y=rW.yK8
} Js#c9l{{
catch(IOException e){e.printStackTrace ();} `TsfscN
catch(Exception e){e.printStackTrace ();} vDOeBw=
} IO_H%/v"jC
7erao-
<ct{D|mm
private void processErrorCode(int nErrorCode) #WpO9[b>
{ Z*e7W O.
System.err.println("Error Code : " + nErrorCode); t@19a6:Co
} nt[0krG
" Gn; Q-@
yZ)ScB^
//停止文件下载 s*#|EdD6@
public void siteStop() #XY]@V\
{ cwC,VYVl
bStop = true; J2[QHr&tn
for(int i=0;i<nStartPos.length;i++) qP<,"9!I
fileSplitterFetch.splitterStop(); \T]"pE+8l
UZX)1?U
>qUO_>
} 8"*$e I5
} >%3c1
//负责部分文件的抓取 :3n.nKANr
**FileSplitterFetch.java ng<`2XgU
*/ tw3d>H`
package NetFox; 'IW+"o
kWz%v
rqh,BkQ0t
import java.io.*; QBn>@jq
import java.net.*; &{=~)>h
Tk2kis(n
m[7:p{
public class FileSplitterFetch extends Thread { h'fD3Gr&
Sf'5/9<DW+
w+$gY?%
String sURL; //File URL q(p0#Mk,E
long nStartPos; //File Snippet Start Position eB@i)w?@o
long nEndPos; //File Snippet End Position =K>Z{%i
int nThreadID; //Thread's ID I2DmM"-|
boolean bDownOver = false; //Downing is over aQmL=9
boolean bStop = false; //Stop identical d=KOV;~);
FileAccessI fileAccessI = null; //File Access interface \j;uN#)28
cnPXvD^kY
(MIw$)#^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException xR&,QrjQG
{ dS&8R1\>1
this.sURL = sURL; jRkq^}
this.nStartPos = nStart; K]Cvk%
this.nEndPos = nEnd; ;Gs**BB&
nThreadID = id; C;) xjZiR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _~(Xd@c(
} :{ T#M$T
3ElpS^2W
l=]vC +mU
public void run() n1/lE)
{ Wkk Nyg,
while(nStartPos < nEndPos && !bStop) 1;gSf.naG
{ 2!otVz!Mh
">QY'r
bgK(l d`
try{ QPcB_wUqu
URL url = new URL(sURL); >oNk(. %
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z%{f[|h9}
httpConnection.setRequestProperty("User-Agent","NetFox"); '> Q$5R1
String sProperty = "bytes="+nStartPos+"-"; U ^9oc&
httpConnection.setRequestProperty("RANGE",sProperty); S+y2eP G
Utility.log(sProperty); =5M>\vt]
F`Y<(]+
KUyJ"q<W
InputStream input = httpConnection.getInputStream(); YcV~S#b
//logResponseHead(httpConnection); h^*{chm]
<"+C<[n.
RM+E
byte[] b = new byte[1024]; KRZV9AJ
int nRead; oCYD@S>h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /nP=E
{ 6;pREM+
nStartPos += fileAccessI.write(b,0,nRead); v+sbRuo8
//if(nThreadID == 1) r*wKYb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F]*-i 55S
} 7&)F;;H
k9xKaJ%1
cj<@~[uw
Utility.log("Thread " + nThreadID + " is over!"); gAY2|/,
bDownOver = true; `@D4?8_
//nPos = fileAccessI.write (b,0,nRead); !gf3%!%
} UVJ(iNK"
catch(Exception e){e.printStackTrace ();} VC(|t} L4
} [alXD_
} 0cUt"(]
~m?~eJK#a
K-u/q6ufK
//打印回应的头信息 j2Y(Q/i
public void logResponseHead(HttpURLConnection con) ;#i$0~lRl
{ o{LFXNcg[
for(int i=1;;i++) ,GnU]f
{ z0[ZO1Fo(
String header=con.getHeaderFieldKey(i); >2 qP
if(header!=null) RWo B7{G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B-|Zo_7
Utility.log(header+" : "+con.getHeaderField(header)); UYOn p7R<
else \W^+vuD8
break; N=wy)+
} y}HC\A77uD
} KgWT&^t
p ri{vveN@
=3C)sz}
public void splitterStop() Zwns|23n
{ r![JPhei
bStop = true; n^02@Aw
} -(}1o9e\7
tlgvBRH>
"'B%.a#k
} Sg>0P*K@
!y~b;>887
j]"xck
/* !@Lc/'w
**FileAccess.java CHit
*//文件访问(定位，写) E57{*C
package NetFox; 1<`7MN
import java.io.*; p\;)^O4
~J{[]wi
E}9ldM=]s
public class FileAccessI implements Serializable{ C}'="g^=sl
?(8%SPRk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y?#J`o- O
RandomAccessFile oSavedFile; B!ibE<7,
long nPos; g+)\/n|
yKEFne8^
,D2_Z]
public FileAccessI() throws IOException gCr|e}w-
{ L_K\i?
this("",0); _C,@eu"9V
} f\U&M,L\'
UH-uU~
{FY[|:Cp
public FileAccessI(String sName,long nPos) throws IOException zf>^2t*\
{ xevP2pYG:
oSavedFile = new RandomAccessFile(sName,"rw"); n(YHk\2
this.nPos = nPos; /8t+d.r;/
oSavedFile.seek(nPos); l)*,18n
} cievC,3*
CN~NyJL H
PFy;qk
public synchronized int write(byte[] b,int nStart,int nLen) 65#:2,s
{ ?VP!1O=J
int n = -1; / &D$kxz
try{ \R\@t]>Y
oSavedFile.write(b,nStart,nLen); L2.`1Aag
n = nLen; k5;Vl0Ho
} KI@
catch(IOException e) xf"5<PTW</
{ E+ 3yN\X(
e.printStackTrace (); auTTvJ
} ]Bd3d%
)QCM2
&_/%2qs
return n; "=\_++
} 6eYf2sZ;J
=l2Dm
uV}WSoq[
} 0O,T=z[+>
oA;Ty7s
^h6$>n5
/* Vm;Qw
**SiteInfoBean.java 6$fnQcpJ
*/ ~J>gVg%66
package NetFox; =Cy>$/H64
sC5uA .?>9
4!~ .6cp3
public class SiteInfoBean { Qj<{oZp&
YG 5Z8@kH
0SYf<$
private String sSiteURL; //Site's URL _p J_V>l
private String sFilePath; //Saved File's Path ca/o#9:N`:
private String sFileName; //Saved File's Name yaRcBT?
private int nSplitter; //Count of Splited Downloading File !\#Wk0Ku
%:w% o$
"4ozlWx
public SiteInfoBean() s w.AfRQP
{//nSplitter的缺省值为5 FL#g9U>
//default value of nSplitter is 5 S`@6c$y k
this("","","",5); ^/C$L8#
} {#1j"
2'<=H76
De nt?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Awa|rIM
{ |v$%V#Bo
sSiteURL= sURL; \YlF>{LVe
sFilePath = sPath; -M:hlwha
sFileName = sName; C?60`^
this.nSplitter = nSpiltter; +eBMn(7Cgv
A!ioji+{[
{;iHYr-zs
} /}nrF4S
_D>as\dP
88#qu.
public String getSSiteURL() hk@`N;dn
{ B]|6`UfB
return sSiteURL; vNz;#Je
} \U!@OX.R'M
OJ35En
d2A wvP
public void setSSiteURL(String value) I>H;o{X#
{ %|*nmIPq(
sSiteURL = value; Foe>}6~{?
} 9'n))%CZ.
xi?P(sA
^$=tcoQG
public String getSFilePath() e|b~[|;*=
{ `&u<aLA
return sFilePath; [Y22Wi
} fwi};)K
1C0Y0{6,
Hz]4AS
public void setSFilePath(String value) DIG0:)4R.
{ 5@ bc(H
sFilePath = value; c{mKra
} >P\h,1
A,m4WO_q3
DHm[8 Qp
public String getSFileName() ~JwpNJs
{ ShWHHU(QQ
return sFileName; G{NSAaD[
} CJ9cCtA
%XJQ0CE<(
w.J%qWJq
public void setSFileName(String value) GSz @rDGY
{ k-WHHoU>o
sFileName = value; Qj 6gg
} cc|CC Zl
*.m{jgi1X
Yzj%{fkh
public int getNSplitter() IjG5X[@
{ /~i.\^HX
return nSplitter; Gr5`1`8|
} ~@T+mHny
X0y?<G1(a
i>Z|65
public void setNSplitter(int nCount) Lw>-7)
{ F8{ldzh
nSplitter = nCount; M`0(!Q}
} ]urK$
} 2#z=zd
Qm.z@DwFM{
;W7hc!
/* mi7sBA9L8
**Utility.java l^k+E-w\
*/ Mjb 1
package NetFox; |x &Z~y
V~OUE]]Q
O.*jR`l
public class Utility { { EA2
`nT?6gy
2BHKS-J*
public Utility() W1xf2=z`)T
{ 2Sge
pO"m~mpA
1^aykrnQ>
} ;"1/#CY773
&&X$d!V
//线程睡眠 bt;lq!g
public static void sleep(int nSecond) fd4;mc1T
{ @&?a]>L
try{ W|;nJs:e
Thread.sleep(nSecond); P?^JPbfV
} 3PfiQ|/b
catch(Exception e) <z^SZ~G
{ }%eDEM
e.printStackTrace (); 5pO]vBT
} hzaU8kb
} cX2$kIs;
__8&Jv\
//日志 KzV.+f
public static void log(String sMsg) FyCBNtCv
{ e\`wlaP,
System.err.println(sMsg); z~F37]W3[
} {3_Gjb5\\4
}A-{6Qe
f[x~)=
public static void log(int sMsg) V {p*z
{ x@htx?
System.err.println(sMsg); J;S-+
} (FuEd11R
} {`a(Tl8V
8Bq-0=E
8+9\7*
/* Tj=gRQ2v
**TestMethod.java UL&} s_
*/ -(!uC+BZX
package NetFox; Kk7GZ
U<Vy>gIC
=tq1ogE
public class TestMethod { 6VC-KY
4iwf\#
v{r1E]rY
public TestMethod() iecWa:('
{ ///xx/weblogic60b2_win.exe /^Y[*5
try{ GjEqU;XBi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kL|\wci
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rR\;G2p)
SiteFileFetch fileFetch = new SiteFileFetch(bean); EOhC6>ATh
fileFetch.start(); q]K'p,'
} 975 _d_U
catch(Exception e){e.printStackTrace ();} xpAok]
^CUSlnB\(
I`NUurQTX
} n,CD
!:3^ hb
M_Bu,<q^
public static void main(String[] args) *#zS^b n
{ m~;B:LN<
new TestMethod(); !~)90Z!
} u\f3qc,]F
} ?IILt=)<
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