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)); b:}wR*Adc
} bik] JIM
for(int i=0;i<nEndPos.length-1;i++) ?YkO+?}+
{ "xvV'&lQ
nEndPos = nStartPos[i+1]; KRnB[$3F1
} m+72C]9
nEndPos[nEndPos.length-1] = nFileLength; 2R_opbw
} C,OB3y
} haEZp6Z
*#prSS
CO:m]oj
//启动子线程 bBeFL~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I&'S2=s
for(int i=0;i<nStartPos.length;i++) K^]?@oHO
{ Mv7w5vTl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~WYE"(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 75hFyh;u
nStartPos,nEndPos,i); .v #0cQX+.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8T>3@kF
fileSplitterFetch.start(); y]QQvCJr3d
} M/8#&RycQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,%)WT>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &;NNUT>Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |k7ts&2
nEndPos = " + nFileLength); Q^1#xBd
// fileSplitterFetch[nPos.length-1].start(); MQ9M%>
,z0~mN
vjs|!O=oH
//等待子线程结束 gNEzlx8A
//int count = 0; H649J)v+m
//是否结束while循环 ;i-D~Np|
boolean breakWhile = false; ^huBqEs
VuO)
HonAK
while(!bStop) 32iWYN
{ #cp$ltY
write_nPos(); PoBukOv
Utility.sleep(500); NR;S3-Iq(
breakWhile = true; G(7\<x:
o3TBRn,
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for(int i=0;i<nStartPos.length;i++) nL7S3
{ NSiYUAug
if(!fileSplitterFetch.bDownOver) 6bRQL}[
{ k<j)?_=`
breakWhile = false; i)`zKbK
break; *mK);@pL
} xyz\;3
} lvz:UWo
if(breakWhile) b]so9aCz
break; "b1R5(Ar
K;ry4/Vap
%`s9yRk9>E
//count++; ,h wf
//if(count>4) pxCGE[@`
// siteStop(); {*ko=77$*
} V%{9o
]mO+<{{4X
jKb=Zkd
System.err.println("文件下载结束！"); d9[6kQ]
} H z< M
catch(Exception e){e.printStackTrace ();} Skk3M?
} vUIK4uR.
tI!R5q;k
X/;"CM
//获得文件长度 [hv3o0".
public long getFileSize() g*w-"%"O
{ .2(@jx,[
int nFileLength = -1; >ihe|WN
try{ 9TXm Z
URL url = new URL(siteInfoBean.getSSiteURL()); +}G>M=t::
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k.? T.9
httpConnection.setRequestProperty("User-Agent","NetFox"); 8tFyNl`c
$CQwBsYb=
v;F+fOo
int responseCode=httpConnection.getResponseCode(); ,rl <ye*&
if(responseCode>=400) rY_C3;B
{ -JyODW#j
processErrorCode(responseCode); bbPd&7
return -2; //-2 represent access is error i_ODgc`H
} )Ido|!]0d
si mX
z7l;|T
String sHeader; `aWwF} +Y
NM.f0{:cj
^kR^ QL$
for(int i=1;;i++) n'ca*E(
{ ->"h5h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gU 2c--`
//Utility.log(in.readLine()); ae(]9VW
sHeader=httpConnection.getHeaderFieldKey(i); f@.Q%+!4
if(sHeader!=null) kAQ\t?`x
{ Vp-OGX[
if(sHeader.equals("Content-Length")) <2@<r t{
{ <hF~L k ,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @9kk f{?
break; RWh}?vs_
} W!Ct[t
} hDkqEkq1R
else ~NW5+M(u
break; [2j(\vC!
} \tw#pk
} ``YL] <<
catch(IOException e){e.printStackTrace ();} +KwF U
catch(Exception e){e.printStackTrace ();} %},S#5L3
PK`(qK9
Xde=}9
Utility.log(nFileLength); r;6YCI=z
JpHsQ8<
v,.n/@s|X
return nFileLength; 1.d9{LO[-
} MPEBinE?
7Hkf7\JY
Xi`U`7?D(=
//保存下载信息（文件指针位置） 2.&V
private void write_nPos() 1oW]O@R
{ Vqp.jF1|
try{ d<cbp[3F
output = new DataOutputStream(new FileOutputStream(tmpFile)); uxJiec`&
output.writeInt(nStartPos.length); [\M?8R$)
for(int i=0;i<nStartPos.length;i++) ! {o+B^^
{ AFhG{G'W
// output.writeLong(nPos); ` Ehgn?6'
output.writeLong(fileSplitterFetch.nStartPos); 8/kO9'.P
output.writeLong(fileSplitterFetch.nEndPos); b yreleWo
} o >4>7
output.close(); Zz*mf+
} [6gHi.`p'
catch(IOException e){e.printStackTrace ();} .j<B5/+
catch(Exception e){e.printStackTrace ();} Hr,lA(
} 0v)mgrl=,
?bYQZJ>&
PH4bM
//读取保存的下载信息（文件指针位置） Qs[EA_
private void read_nPos() C%7)sLWjJS
{ X1z0'gvh
try{ 4y}a,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^d$e^cU
int nCount = input.readInt(); U &k3
nStartPos = new long[nCount]; ?}Ptb&Vk(
nEndPos = new long[nCount]; o?hw2-mH
for(int i=0;i<nStartPos.length;i++) VKfHN_m*
{ \C\y'H5
nStartPos = input.readLong(); A)a+LW'=u
nEndPos = input.readLong(); cz~11j#
} Ecl7=-y
input.close(); 2+Y`pz47W
} [Ik B/Xbw|
catch(IOException e){e.printStackTrace ();} BL^Hj
catch(Exception e){e.printStackTrace ();} PaI63 !
} o|n0?bThS-
9d(v^T
<EN[s
private void processErrorCode(int nErrorCode) (2(;u1
{ :;u]Y7
System.err.println("Error Code : " + nErrorCode); ej53O/hP
} /@}# KP=
cZF;f{t
,^[37/S
//停止文件下载 0$h$7'a
public void siteStop() 6]A\8Ty
{ 7 ,~Krzv
bStop = true; ,ui'^8{gK
for(int i=0;i<nStartPos.length;i++) jN{xpd
fileSplitterFetch.splitterStop(); Jj!tRZT
;HwJw\fo
T ]nR XW$
} -ns a3P
} X_S]8Aa
//负责部分文件的抓取 Fm~}A4
**FileSplitterFetch.java mNB ]e5;N
*/ %z_b/yG
package NetFox; -@?>nLQb
bN%MT#X
1ucUnNkcV
import java.io.*; U1tPw`0h
import java.net.*; TK?N^ly
z#67rh{
D(?#oCCA
public class FileSplitterFetch extends Thread { nE$ V<Co}
d"uM7PMs7x
05zdy-Fb
String sURL; //File URL TbM*?\7
long nStartPos; //File Snippet Start Position `.Q3s?1F
long nEndPos; //File Snippet End Position }j@@
int nThreadID; //Thread's ID \>k#]4@rp
boolean bDownOver = false; //Downing is over |L-juT X9
boolean bStop = false; //Stop identical (D3m5fO
FileAccessI fileAccessI = null; //File Access interface l zknB
3nGK674;z
A^7Zy79
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %cjav
{ l_IX+4(@b|
this.sURL = sURL; 9e*poG
this.nStartPos = nStart; z]_CFo1'l
this.nEndPos = nEnd; 9cPucKuj
nThreadID = id; "Z?":|%7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pl/$@K?L
} S$:S*6M@"
'B:De"_(N
Q%d[U4@
public void run() E*"E{E7
{ v^E2!X
while(nStartPos < nEndPos && !bStop) td$Jx}'A
{ #Ih(2T i
Z4sjH1W
TyXOd,%zl
try{ IUG.q8
URL url = new URL(sURL); Efd[ZJxS6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +@v} (
httpConnection.setRequestProperty("User-Agent","NetFox"); 2xm?,p`
String sProperty = "bytes="+nStartPos+"-"; du)G)~
httpConnection.setRequestProperty("RANGE",sProperty); #Jb$AA!z
Utility.log(sProperty); :|(B[
+& Qqu`)?F
@2O\M ,g5
InputStream input = httpConnection.getInputStream(); 6%axbB
//logResponseHead(httpConnection); K?eo)|4)DB
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+T;qvx6
byte[] b = new byte[1024]; }Ec"&
int nRead; lK@r?w|<M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '*.};t~;"d
{ n-WvIy
nStartPos += fileAccessI.write(b,0,nRead); >qZRIDE5$
//if(nThreadID == 1) mJqP#Unik
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =~*u(0sJa
} -p~B -,
K|!)<6ZsG7
P1jkoJ
Utility.log("Thread " + nThreadID + " is over!"); c3mlO[(
bDownOver = true; _Y~?.hs^
//nPos = fileAccessI.write (b,0,nRead); v:b%G?o
} |9JYg7<
catch(Exception e){e.printStackTrace ();} LRgk9*@,
} 94/}@<d-=
} o4795r,jz
IC42O_^
69L&H!<i:
//打印回应的头信息 ]kvE+m&p}^
public void logResponseHead(HttpURLConnection con) '93&?
{ Q5ao2-\
for(int i=1;;i++) Ric$Xmu
{ b`=rd 4cpU
String header=con.getHeaderFieldKey(i); M?97F!\U
if(header!=null) 8i"fhN3?Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xbIA97g-O,
Utility.log(header+" : "+con.getHeaderField(header)); 5$w1[}UUd
else _E7eJSM.
break; @n3PCH6:Ao
} }%|OnEk"
} <9vkiEo
y3GIR f;>
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public void splitterStop() ~a Rq\fx{
{ W3kilhZ
bStop = true; nwYeOa/t
} ,kI1"@Tu
m-]"I8[
Z m>69gl
} 1owoh,V6
6ZJQ '9f
<z PyID`
/* FUqiP(A
**FileAccess.java s,=^V/c
*//文件访问(定位，写) 7va%-&.&t
package NetFox; >@o*v*25
import java.io.*; .l!Z=n|
^ TS\x/P
]a()siT
public class FileAccessI implements Serializable{ u^$ CR
%8/$CR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LgYzGlJp
RandomAccessFile oSavedFile; P7!Sc
long nPos; IG\\RYr
aJts
>#Yq&@G
public FileAccessI() throws IOException Bf.RYLsh6
{ xYq8\9Qb
this("",0); qYs6PLC
} 1zffPC8jl
c1f6RCu$b
'_%Jw:4k
public FileAccessI(String sName,long nPos) throws IOException 1Ppzch7
{ K`sm
oSavedFile = new RandomAccessFile(sName,"rw"); ' =kX
this.nPos = nPos; :0l(Ll KD
oSavedFile.seek(nPos); ))vwofkw4
} l%O-c}X
3`y:W9!u
A{k@V!A%
public synchronized int write(byte[] b,int nStart,int nLen) {u5@Yp
{ ? "gy`oCv
int n = -1; 6r`g+Js/
try{ +}!eAMQ
oSavedFile.write(b,nStart,nLen); 8MdKH7
n = nLen; c}lgWu~
} >X]<s^
catch(IOException e) s?G@k}{
{ , /pE*Yk
e.printStackTrace (); /:DxB00
} b< rM3P;
\]D;HR`vo
e-WaK0Ep
return n; )8_0d)
} [ kknY+n1
Ptg73Gm&R
'nul{RE*
} UkC\[$-"\
cjL!$OE6
K{c^.&6D
/* 2;3q](d
**SiteInfoBean.java =[$*PTe
*/ ^s-3U
package NetFox; kF5}S8B
xiiZ'U
p ,!`8c6
public class SiteInfoBean { DI\^+P
9f "*Oj
CfAqMH*ip
private String sSiteURL; //Site's URL T"z!S0I
private String sFilePath; //Saved File's Path tPUQ"S
private String sFileName; //Saved File's Name qy!G&
private int nSplitter; //Count of Splited Downloading File er_aol e
SaNx;xgi
$]vR,E
public SiteInfoBean() J]%P fWV
{//nSplitter的缺省值为5 ^a]:GPc
//default value of nSplitter is 5 nL$tXm-x
this("","","",5); Au {`oxD
} zAH+{4lC+
biJU r^n
%ug`dZ/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5H79) n>
{ OygYP
sSiteURL= sURL; |(/"IS]
sFilePath = sPath; F"q3p4-<>
sFileName = sName; 1)%o:Xy o
this.nSplitter = nSpiltter; </fnbyGR
w-KtxG(
QMIQy
} _CgD7d
$6_J`7
\6N\6=t!A
public String getSSiteURL() YC$pT
{ 6O"0?wG+
return sSiteURL; e'jR<ln|
} 2`z+_DA
E?;W@MJi
m'S-h'a
public void setSSiteURL(String value) BH}u\K
{ N\p3*#M
sSiteURL = value; .RT5sj\d
} 5Hr"}|J<8
UkdQ#b1
[~J4:yDd=
public String getSFilePath() R_^:<F0
{ :( `Q4D~l
return sFilePath; .{Xi&[jw
} k~?@~xm,R
Awj`6GeJ
f_ ::?
public void setSFilePath(String value) -Ju!2by
{ xGA%/dy,;
sFilePath = value; 6 2LZ}yn_"
} 0]Li"Wb
]t,ppFC#
qn<~ LxQ
public String getSFileName() ^Ab|\5^3
{ Oz+>I^Q
return sFileName; ]!f=b\-Av
} _K9jj
A_[65'*b
=.uE(L`]NA
public void setSFileName(String value) }NUP[%
{ 8T%z{A1T
sFileName = value; old}}>_
} +pE-Yn`YS
O9qEKW)a
vX{]_
public int getNSplitter() $GcVC (]
{ lAoH@+dyA+
return nSplitter; DukCXyB*l
} ?(mlt"tPk
-O ej6sILO
?&Lb6(}e
public void setNSplitter(int nCount) /JvNJ f
{ kY*D s;
nSplitter = nCount; Pp}j=$&j\
} `=FfzL
} X&K1>dgWP
$FD0MrB_+
N[AX29
/* . [C~a
**Utility.java xL mo?Y*
*/ fFsA[@5tul
package NetFox; 2"NJt9w
?gTY!;$P
3.8d"
public class Utility { [1N*mY;
2r1.,1
s:Memvf
public Utility() zX)uC<
{ L"AZ,|wIk
&'R\yX<J)
b,I$.&BD
} Yw./V0Z{@
'(ql7
//线程睡眠 q),yY]5
public static void sleep(int nSecond) JD,/oL.KA
{ A9[l5E
try{ 32dR`qb
Thread.sleep(nSecond); 3]V"9+
} :]:q=1;c
catch(Exception e) UE*M\r<
{ hH%@8'1v
e.printStackTrace (); 2jA-y!(e
} JEj.D=@[
} D;m>9{=
|o6B:NH,rg
//日志 58WL8xu
public static void log(String sMsg) >8EIm
{ yw2sK7
System.err.println(sMsg); Yf<6[(6 O
} lLl^2[4k5
8M!If
NKh8'=S
public static void log(int sMsg) U@DIO/C,m`
{ H htAD Y
System.err.println(sMsg); %I?uO( @
} :H3qa2p
} @=:( b"Sg
V D-,)f
[$f
/* fmFh.m.+N
**TestMethod.java 6/ F]ncwG
*/ aNw8][
package NetFox; Y=\;$:L[
jgbE@IA@!'
cjp H hoW
public class TestMethod { n-0RA~5z
Q`'w)aV
g"^<LX-
public TestMethod() 6Xbo:#
{ ///xx/weblogic60b2_win.exe $SA8$!:
try{ {p-&8-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N"@aisi)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yMB*/vs
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0escp~\Z
fileFetch.start(); !-)Hog5\
} 9+_SG/@
catch(Exception e){e.printStackTrace ();} -ich N/U]s
gWL'Fl}H
$0=f9+@5
} Z2!O)8
wgp{P>oBX
9Eu.Y
public static void main(String[] args) 3%p^>D\
{ 4At{(fwW
new TestMethod(); |Q[[WHqj2f
} t&*X~(Yb!
} -YPUrU[)
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