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)); l]oGhM;
} <0JW[m
for(int i=0;i<nEndPos.length-1;i++) <9\_b6
{ zh*NRN
nEndPos = nStartPos[i+1]; <:q]t6]$
} JOenVepQ,
nEndPos[nEndPos.length-1] = nFileLength; J5@_OIc1y
} \DeZY97p%
} tnRq?
T(J&v|FK
gbXzD`WQ
//启动子线程 lq.AQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #V4_.t#
for(int i=0;i<nStartPos.length;i++) 8Vl!&j0s^
{ j><.tA~i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #FTXy>W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M={k4r_t
nStartPos,nEndPos,i); <:RU,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NFmB ^@k
fileSplitterFetch.start(); TQID-I
} `A&64D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XImb"7|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jUW{Z@{U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v,Ep2$
nEndPos = " + nFileLength); zLf^O%zN
// fileSplitterFetch[nPos.length-1].start(); n+Fl|4
|{t}ULc
{^MR^4&}(
//等待子线程结束 %z.u % %
//int count = 0; O?8G
//是否结束while循环 xV<NeU
boolean breakWhile = false; MttVgNV
<aL$d7
X@|
while(!bStop) 6M612
{ N-_2d*l3
write_nPos(); ymr-kB
Utility.sleep(500); XK(<N<Z@|e
breakWhile = true; ew}C*4qH
}1X,~y]
3<'SnP3mY
for(int i=0;i<nStartPos.length;i++) KY2xKco
{ '=%vf
if(!fileSplitterFetch.bDownOver) |_!xA/_U'T
{ )|Y"^K%Jm
breakWhile = false; h r*KDT^!
break; e:NzpzI"v
} XXxX;xz$
} 0($MN]oZa
if(breakWhile) 15Yy&9D
break; .i[Tp6'%,
o6B!ikz 8
1wGd5>GDA
//count++; 6j_ A{*~Ng
//if(count>4) LT2mwJl
// siteStop(); WmOd1
} |D`Zi>lv
y5+-_x,
Ww)qBsi8
System.err.println("文件下载结束！"); QJGRi
} N \A)P
catch(Exception e){e.printStackTrace ();} 5vg@zH\z
} i"sVk8+o!
C.pNDpx-
(w"zI!
//获得文件长度 d3^LalAp
public long getFileSize() Ha4?I$'$
{ Hdj0! bUx
int nFileLength = -1; Z-]d_Y~m4
try{ +,c;Dff
URL url = new URL(siteInfoBean.getSSiteURL()); 1T!_d&A1o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >/$Q:92T
httpConnection.setRequestProperty("User-Agent","NetFox"); n'%*vdHKm
o(|`atvK
/$I&D}uR`
int responseCode=httpConnection.getResponseCode(); _%Mu{Ni&
if(responseCode>=400) &$vDC M4
{ }Ct_i'Ow
processErrorCode(responseCode); p5G O@^i
return -2; //-2 represent access is error X+bLLW>&
} J"FKd3~:E
NoZz3*j=
.eq-i>
String sHeader; v8-F;>H
_qJ[~'m<^C
_Ndy;MQ
for(int i=1;;i++) w#XE!8`
{ H\^5>ccU>V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q.M3rRh
//Utility.log(in.readLine()); K& 2p<\2
sHeader=httpConnection.getHeaderFieldKey(i); tlqDY1
if(sHeader!=null) <(#cPV@j
{ b\]"r x (
if(sHeader.equals("Content-Length")) Gash3}+
{ N|7<*\o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "0zMx`Dh
break; D.R5-
} [9aaHf@'
} l<z[)fE{uS
else Kq6m5A]z
break; ~iF*+\
} p~Dm3^Y
} UxD1+\N6?
catch(IOException e){e.printStackTrace ();} sOU_j4M{
catch(Exception e){e.printStackTrace ();} R0*DfJS:Z
uTB;Bva
@RbAC*Y]g
Utility.log(nFileLength); &v3r#$Hj[
988aF/c
`d3S0N6@
return nFileLength; g<}EL[9[J
} P{QRmEE
nb0<.ICF%R
5g/^wKhKG
//保存下载信息（文件指针位置） K2:r7f
private void write_nPos() ]DC]=F.
{ rv|k8
try{ "eh"'Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); \+L_'*&8
output.writeInt(nStartPos.length); J,m.LpY
for(int i=0;i<nStartPos.length;i++) ~3f#cEP>d}
{ 8a. |CgI#h
// output.writeLong(nPos); `2r21rVntf
output.writeLong(fileSplitterFetch.nStartPos); >[ 72]<6
output.writeLong(fileSplitterFetch.nEndPos); Yn1U@!
} LFGu|](
output.close(); WMh'<'wN_
} Arfq
catch(IOException e){e.printStackTrace ();} s/P\w"/fN
catch(Exception e){e.printStackTrace ();} Hvor{o5|tB
} :CK,(?t
Vy-S9=
YhR?*Di
//读取保存的下载信息（文件指针位置） =bv8W <#
private void read_nPos() +zL=UEBN
{ u$<FKp;I
try{ -@^SiI:C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e$F7wto
int nCount = input.readInt(); {6/%w,{,
nStartPos = new long[nCount]; xW"J@OiKL
nEndPos = new long[nCount]; Dq2eX;c@
for(int i=0;i<nStartPos.length;i++) (T'inNbJe
{ 3P-#NL
nStartPos = input.readLong(); Ej.D!@
nEndPos = input.readLong(); %$sWNn
} o/=K:5
input.close(); OQ!mL3f
} 8eOQRC33
catch(IOException e){e.printStackTrace ();} .iew5.eB+
catch(Exception e){e.printStackTrace ();} \dufKeiS&a
} ?kS5=&<
-t*C-C'"|
5-]%D(y
private void processErrorCode(int nErrorCode) \N"K^kR4
{ /I6?t=?<
System.err.println("Error Code : " + nErrorCode); hk,Q=};
} ?cg+RNI
If4YqBG
!4oYQB
//停止文件下载 #axRg=d?K
public void siteStop() {bc<0
{ .v;2Q7X
bStop = true; h)A+5^:^
for(int i=0;i<nStartPos.length;i++) A]=?fyPh{'
fileSplitterFetch.splitterStop(); |ZRl.C/e
hj4A&`2
>O\-\L
} jv_sRV
} xsAF<:S\
//负责部分文件的抓取 r-Dcc;+=Q
**FileSplitterFetch.java 4&t6
*/ EQ=Enw1[
package NetFox; |: nuT$(
gB~SCl54
.!9]I'9M
import java.io.*; -@J;FjrXmP
import java.net.*; fylaH(LER
KCCS7l/
rxDule3m
public class FileSplitterFetch extends Thread { Ir}&|"~H
%8 4<@f&n]
,][+:fvS
String sURL; //File URL XUSfOf(
long nStartPos; //File Snippet Start Position C($`'~b
long nEndPos; //File Snippet End Position +Z{4OJK
int nThreadID; //Thread's ID 4AF"+L
boolean bDownOver = false; //Downing is over 8{d`N|k
boolean bStop = false; //Stop identical 9)4N2=
FileAccessI fileAccessI = null; //File Access interface uHf~KYL
PDpIU.=!0
0p[$8SCJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hw1ZTD:Y
{ j,G/[V
this.sURL = sURL; BO{J{
this.nStartPos = nStart; @pG\5Jnf
this.nEndPos = nEnd; aa".d[*1
nThreadID = id; XhIgzaGVu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q_ 5xsTlTR
} k| jCc
%b!p{p
%@rh\Z
public void run() ;^ /9sLW?#
{ dmF<J>[
while(nStartPos < nEndPos && !bStop) H%sQVE7m
{ *2>%>qu
m&$H?yXW>
\<PX'mnO
try{ IO6i
URL url = new URL(sURL); IH:Hfv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }7C{:H2d
httpConnection.setRequestProperty("User-Agent","NetFox"); z2dM*NMK
String sProperty = "bytes="+nStartPos+"-"; lI5{]?'
httpConnection.setRequestProperty("RANGE",sProperty); [I^SKvM
Utility.log(sProperty); I &m~ cBj<
a}Ov@7
m_]"L
InputStream input = httpConnection.getInputStream(); z5i!GJB
//logResponseHead(httpConnection); YobIbpo
5jsnE )
Q5jP`<zWU
byte[] b = new byte[1024]; Z]Qm64^I
int nRead; Y@r#:BH)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hrXN38-
{ '+}hVfN
nStartPos += fileAccessI.write(b,0,nRead); ?`w ~1
//if(nThreadID == 1) `i.f4]r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f|q6<n_nM
} Dn6DkD!
gB0)ec 0
:#gz)r
Utility.log("Thread " + nThreadID + " is over!"); OOv"h\,
bDownOver = true; \]r{73C
//nPos = fileAccessI.write (b,0,nRead); -J[D:P.Z
} a.Mp1W
catch(Exception e){e.printStackTrace ();} G;^iwxzhO
} Cu`ZgKLQ
} c~tkY!c
2'x_zMV
.KB*u*h
//打印回应的头信息 :zZtZT!
public void logResponseHead(HttpURLConnection con) e~-Dk .i
{ TIvLY5 HG
for(int i=1;;i++) fO:*85%}7
{ zY#U]Is
String header=con.getHeaderFieldKey(i); ^QnVYTM
if(header!=null) +0=RC^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *PMql$
Utility.log(header+" : "+con.getHeaderField(header)); ++kiCoC
else ,)QmQ^/
break; PDir?'
} / _cOg? o
} Et- .[
HQE#O4
(Ux%7H_d
public void splitterStop() $ &^ ,(z9
{ yx}:Sgv%
bStop = true; `V?{
} i>rn!?b
^%<v| Y(X
>*_?^F_
} vw(};)8
'/"(`f,
\J13rL{<
/* 7"QcvV@p
**FileAccess.java +(P;4ZOmB
*//文件访问(定位，写) G_o/ lIz"
package NetFox; @.g4?c
import java.io.*; SOUA,4
huQ1A0(no
aI\VqOt]
public class FileAccessI implements Serializable{ '@W72ML.
U}5uy9A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 JZc5U}i
RandomAccessFile oSavedFile; M.128J+xfS
long nPos; #A))#sT'R
mj,r@@k:=+
d3![b1
public FileAccessI() throws IOException |MRxm"]A
{ JZ<O-G+
this("",0); @vv`86bm
} UtWoSFZ'o!
6-JnT_
Z@h]dU5%a
public FileAccessI(String sName,long nPos) throws IOException My[L3KTTp
{ Dho~6K}"
oSavedFile = new RandomAccessFile(sName,"rw"); ooD/QZUE
this.nPos = nPos; L3W ^ip4
oSavedFile.seek(nPos); AI)9E=D%
} dE^'URBiA
epwXv|aSZ
b"zq3$6*
public synchronized int write(byte[] b,int nStart,int nLen) 9S<W~# zz
{ r>G$u
int n = -1; %_z]iz4
try{ fkI<RgM
oSavedFile.write(b,nStart,nLen); Zkz:h7GUG-
n = nLen; @&~BGh
} mDq01fU4
catch(IOException e) bWyXDsr+
{ :*8@MjZ4
e.printStackTrace (); xL!05du
} HN3 yA1<[V
JRNyvG>j
0\mM^+fO
return n; <iMkHch
} {<_}[} XY
I{2e0
zJV4)
} ~<$8i}7
Im Tq`
B]hZ4.B1
/* '6aH*B:}*;
**SiteInfoBean.java 8^~ljf]6
*/ #._!.P
package NetFox; ybB}|4d&
Z>{8FzP.F
cg$~.ytPK
public class SiteInfoBean { p*N+B o
!^N/n5eoz
!#X^nlc
private String sSiteURL; //Site's URL 6^wiEnA
private String sFilePath; //Saved File's Path !",@,$
private String sFileName; //Saved File's Name CZuxH
private int nSplitter; //Count of Splited Downloading File YGNX+6Lz
zxj!ihs<
&,#VhT![
public SiteInfoBean() {6KU.'#iF
{//nSplitter的缺省值为5 5i#B?+Y
//default value of nSplitter is 5 c8yD-U/-
this("","","",5); P EbB0GL
} KL|B| u
8!T^KMfz
kg-%:;y.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YZnrGkQ
{ Vk-_v5
sSiteURL= sURL; rkzhN59;
sFilePath = sPath; yRy9*r=
sFileName = sName; In 1.R$O
this.nSplitter = nSpiltter; ~fgv7=(!
L%BWrmg
GY4yZa
} $]hf2Yr(
))MP]j9 T
BY 1~\M
public String getSSiteURL() S#""((U$
{ bLUn0)c
return sSiteURL; !<~Ig/
} p;B +g X
gG$o8c-
'-*r&:
public void setSSiteURL(String value) :q= XE$%H
{ ,= PDL
sSiteURL = value; Mc\lzq8\ 1
} EdU3k'z$
6Qo6T][
iffU}ce
public String getSFilePath() E O}(MXS
{ ^oP]@r"qy
return sFilePath; @emZwN"m
} uD5i5,q1Hs
gVuN a)
=CJs&Qa2
public void setSFilePath(String value) |, :(3Ml
{ Dp'/uCW)
sFilePath = value; [6D>2b}:{[
} t?{B*
x^;nfqn|
JD>!3>S)?
public String getSFileName() {UhZ\qe
{ +\E\&^ZQ
return sFileName; Oc8+an1m
} ?W|POk}
x,V_P/?%
weDv[b5i
public void setSFileName(String value) L Y M`
{ ES+&e/G"ds
sFileName = value; G9gvOEI/
} Eod2vr=Q
LRmO6>y
G(4k#jB
public int getNSplitter() XrvrN^'
{ EXzY4D ^
return nSplitter; *r_.o;6
} 6z(_^CY
ZBYmAD
kj[[78
public void setNSplitter(int nCount) Fb*;5VNU.
{ _,'UP>Si
nSplitter = nCount; /)G9w]|T
} B[*i}k%i
} n1LS*-@
dp?uq'
^hgpeu
/* gi`ZFq@
**Utility.java A76=^iw
*/ ;S%wPXj&
package NetFox; x_Z~k
.=NK^
yWs/~5[F
public class Utility { >!wwXhH(
%AJdtJ@0H
B^OhL!*tI
public Utility() -8TLnl~[
{ O 8fh'6
'J\%JAR@
+uH1rF_&@
} RS93_F8
[~;9Mi.XL
//线程睡眠 yb]a p
public static void sleep(int nSecond) \t(/I=E8/
{ KSexG:Xb
try{ $V+ze*ra
Thread.sleep(nSecond); D]0#A|nF
} %++q+pa
catch(Exception e) +F@9AO>LF
{ ?$gEX@5h
e.printStackTrace (); mbd@4u
} >Qi2;t~G
} ;+5eE`]a/L
Kg%_e9nj#
//日志 YlYTH_L>E
public static void log(String sMsg) dtnAMa5$T
{ Y`_6Ny="
System.err.println(sMsg); Z)ObFJMG5
} S |B7HS5
>Rr]e`3wG
eHv/3"Og
public static void log(int sMsg) ^y??pp<1J
{ 5ecqJ
System.err.println(sMsg); uh GL1{
} Vdjca:`
} f6z[k_lLN
O/FQ'o1F
KI#hII[Q.
/* K/08F|]a
**TestMethod.java Xf.SJ8G
*/ R[9[lQ'vR
package NetFox; 5` Q#2
}96^OQPE
Q2+e`
public class TestMethod { ,H|V\\
|i|>-|`!
P>)qN,a
public TestMethod() p{88v3b6
{ ///xx/weblogic60b2_win.exe khyVuWN
try{ QYg2'`(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q.!D2RZc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =i `o+H
SiteFileFetch fileFetch = new SiteFileFetch(bean); j{nL33T%
fileFetch.start(); -`A6K!W&~p
} ['{mW4i
catch(Exception e){e.printStackTrace ();} k3u3X~u
Id9hC<8$dq
mgg/i@(
} Z~v.!j0
_O)~<Sk-*z
c!j$-Ovm
public static void main(String[] args) Sl{]Z,
{ `vUilh ^c
new TestMethod(); t}]=5)9<
} 1_f(;WOg
} va| 1N/&
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