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)); 9B3}LVg\
} *(*XNd||
for(int i=0;i<nEndPos.length-1;i++) .8|5;!`WB
{ FEA/}*2F
nEndPos = nStartPos[i+1]; <@@@Pl!~
} +w@/$datI
nEndPos[nEndPos.length-1] = nFileLength; _8z
} ,(#n8|q4
} #M[Cq= 2
*K=me/ 3
KiNluGNt
//启动子线程 L=<,+m[!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I)G.tJZ e
for(int i=0;i<nStartPos.length;i++) "r{ ^Y??
{ z]i/hU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m%OX< T!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KR4RIJZ_t
nStartPos,nEndPos,i); @|~D?&<\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `jDmbD +=
fileSplitterFetch.start(); ;wr]_@<~
} cXOb=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )jRaQ~Sm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); T=cb:PD{%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nQ'AB~ Do
nEndPos = " + nFileLength); Dw2$#d
// fileSplitterFetch[nPos.length-1].start(); &\r_g!Mh
Yg`z4U'6~
iJu$&u
//等待子线程结束 C1~Ro9si
//int count = 0; ,rQPs
//是否结束while循环 Tj=g[)+K
boolean breakWhile = false; GwlAEhP
v#KE"m
K~z9b4a>
while(!bStop) H*dQTy,
{ }KrZ6cG9#
write_nPos(); kI$X~s$r
Utility.sleep(500); NslaG
breakWhile = true; v*e=oyx[
LZ~$=<
}*0*8~Q'5
for(int i=0;i<nStartPos.length;i++) Yr+ghl/ V
{ "[]72PC
if(!fileSplitterFetch.bDownOver) af7\2g3*
{ ~E7=c3:"
breakWhile = false; >E(IkpZ
break; *W<g%j-a
} P1QGfp0-J
} UBy:W^\g
if(breakWhile) hLLg
break; JSiLG0
QGd"Z lQ
D&&11Iz&
//count++; o//PlG~
//if(count>4) jvos)$;L-
// siteStop(); C0Ti9
} ldm=uW
NvlG@^&S
!.k
System.err.println("文件下载结束！"); ~x}=lKN
} .:s**UiDR
catch(Exception e){e.printStackTrace ();} X*C4NF0
} Fop"m/
uBC*7Mkm
l4Y}<j\;
//获得文件长度 =zW.~(c{
public long getFileSize() PfVjfrI[
{ )Ikx0vDFQ
int nFileLength = -1; ^?tF'l`
try{ >U$,/_uMNW
URL url = new URL(siteInfoBean.getSSiteURL()); [&FWR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M0%):P?x
httpConnection.setRequestProperty("User-Agent","NetFox"); "%Eyb\V!
/ZKO\q
r@(hRl1k'
int responseCode=httpConnection.getResponseCode(); 8>K2[cPD
if(responseCode>=400) f8 M=P.jz
{ ]"M4fA
processErrorCode(responseCode); s?*MZC
return -2; //-2 represent access is error A5gdZZ'x
} C"ZCX6p+$
} Pc6_#
&wZ:$lK#o
String sHeader; l2!4}zI2
52#@.Qa
`795K8
for(int i=1;;i++) QJ s/0iw
{ P A9 ]L
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2}Q)&;u
//Utility.log(in.readLine()); PRCr7f
sHeader=httpConnection.getHeaderFieldKey(i); 9Kyr/6w4-k
if(sHeader!=null) Re b^w,
{ 8f|
if(sHeader.equals("Content-Length")) 0Q5ua`U
{ -K)P|'-?m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [0}^w[
break; ,saf"Ed=
} >c7fg^@
} C@L:m1fz
else ?H3xE=<X
break; 2,<!l(X
} =GjxqIv
} )vk$]<$
catch(IOException e){e.printStackTrace ();} s?5(E}
catch(Exception e){e.printStackTrace ();} TlZ|E '_C
\^3\_T&6
#f@sq5pTO
Utility.log(nFileLength); z>hG'
4jrY3gyBX
,.fGZ4
return nFileLength; ]baO{pJi
} u<\/T&S
^r$P&}Z\b
mi3yiR
//保存下载信息（文件指针位置） e p;_'
private void write_nPos() C;;dCsiV5
{ pFD L5
try{ |k+Y >I&
output = new DataOutputStream(new FileOutputStream(tmpFile)); y4Plm.
output.writeInt(nStartPos.length); 6kKIDEX
for(int i=0;i<nStartPos.length;i++) X4Eq/q"
{ 4>>d "<}C
// output.writeLong(nPos); >kK
output.writeLong(fileSplitterFetch.nStartPos); e ?H`p"l
output.writeLong(fileSplitterFetch.nEndPos); w.Ft-RXA W
} 6P!M+PO
output.close(); mg*[,_3q33
} Vo"\nj
catch(IOException e){e.printStackTrace ();} \ey3i((L
catch(Exception e){e.printStackTrace ();} t*^Q`V wQ
} 6546"sU
;e_n7>'#%
*}0g~8Gp
//读取保存的下载信息（文件指针位置） R b6`k^
private void read_nPos() %Sfew/"R0
{ hHdH#-O:4"
try{ <D pi M`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qV.*sdS>
int nCount = input.readInt(); +X0?bVT
nStartPos = new long[nCount]; Jpws1~
nEndPos = new long[nCount]; sL XQ)Ce
for(int i=0;i<nStartPos.length;i++) ,`MUd0 n
{ xO6)lVd
nStartPos = input.readLong(); +dk}$w[g
nEndPos = input.readLong(); Yyby 1
} W[: n*h
input.close(); {KE858
} 3j(GcR9
catch(IOException e){e.printStackTrace ();} z6b!,lp
catch(Exception e){e.printStackTrace ();} N%:QaCZKw
} Ylll4w62N
9=~"^dp54%
Y_)!U`>N?
private void processErrorCode(int nErrorCode) /N7j5v(
{ *K'(t
System.err.println("Error Code : " + nErrorCode); `$7j:<c=
} O!kBp(?]
vWcU+GBZI
; 7[5%xM
//停止文件下载 `TOm.YZG
public void siteStop() @%fNB,H`
{ gyJ$Jp
bStop = true; &mKtW$K` q
for(int i=0;i<nStartPos.length;i++) Q\Fgc ;.U
fileSplitterFetch.splitterStop(); \;}F6g
)&<BQIv9/
me#VCkr#
} KZ pqbI Z
} a8FC#kfq
//负责部分文件的抓取 xf?*fm?m
**FileSplitterFetch.java dmW0SK
*/ )VID ;l;4
package NetFox; B_anO{3$4
I8)x0)Lx
9^<t0oY
import java.io.*; S v$%-x^t
import java.net.*; k/?5Fs!#
znzh$9tH
@S yGj#
public class FileSplitterFetch extends Thread { mTT1,|
gh|TlvnA
m@R!o
String sURL; //File URL WrQe'ny
long nStartPos; //File Snippet Start Position c%yhODq/
long nEndPos; //File Snippet End Position t{| KL<d]
int nThreadID; //Thread's ID 7/w)^&8
boolean bDownOver = false; //Downing is over c=K .|g,
boolean bStop = false; //Stop identical [84ss;.$
FileAccessI fileAccessI = null; //File Access interface MJd!J]E6
UYn5Pix
J1T_wA_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oQ1>*[e<u
{ KyK%2:
this.sURL = sURL; ^+^#KC8]W
this.nStartPos = nStart; anjU3j
this.nEndPos = nEnd; x4Mq{MrWp
nThreadID = id; ,&rlt+wE
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;"$Wfy
} a.#`>
UR44 iA]
Ds? @LE|
public void run() {M96jjiInf
{ /qa{*"2Qo
while(nStartPos < nEndPos && !bStop) N?TXPY
{ lO! Yl:;m%
//n$#c_}u
{b6| wQ\
try{ X]d;x/2
URL url = new URL(sURL); A}v!vVg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L\)ssOuh
httpConnection.setRequestProperty("User-Agent","NetFox"); )-%3;e<w
String sProperty = "bytes="+nStartPos+"-"; 9&}$C]`
httpConnection.setRequestProperty("RANGE",sProperty); 9AO`Zk{/Ez
Utility.log(sProperty); &#^^UT(nj
/]zn8d
S<H2e{~
InputStream input = httpConnection.getInputStream(); ^pruQp1X
//logResponseHead(httpConnection); ,c<&)6FU]
#$2{l,>
n]^zIe^6
byte[] b = new byte[1024]; $(/=Wn
int nRead; _GS_R%b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L&ucTc=
{ 7ESSx"^B
nStartPos += fileAccessI.write(b,0,nRead); }W^%5o87{
//if(nThreadID == 1) >zFk}/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GdHFgxI
} r#rL~Rsd}
A[:0?Ez=
Ut.%=o;&[
Utility.log("Thread " + nThreadID + " is over!"); m/@ ;N,K
bDownOver = true; !Hq$7j_
//nPos = fileAccessI.write (b,0,nRead); 4zyN>f|
} OGW,[k=2{
catch(Exception e){e.printStackTrace ();} uF,F<%d
} |Hx#Uk#
} 4eH:eCZze
@h7)M:l
P/i{_r
//打印回应的头信息 hOZ:r =%
public void logResponseHead(HttpURLConnection con) O*0%AjT6
{ c\A 4-08
for(int i=1;;i++) \PReQ|[ah
{ +~xY}
String header=con.getHeaderFieldKey(i); 'u@,,FFz[K
if(header!=null) gQ90>P:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >NLG"[\
Utility.log(header+" : "+con.getHeaderField(header)); rlxZ,]ul
else wW &q)WOi
break; hOFC8g
} O0^m_
} )Y4;@pEU
9o%k [n
e1cqzhI=nA
public void splitterStop() HiAj3
{ 7PTw'+{
bStop = true; ) uM*`%
} 6Qtyv
jW]Q-
BoJpf8e'-e
} bu0i#
zF: :?L~
M%&1j >d
/* +;r1AR1)x
**FileAccess.java 0?V{u`*
*//文件访问(定位，写) 0zQ~'x
package NetFox; mIW8K ):
import java.io.*; a]H&k$!c
^IQtXae6M
~mBY_[_s=
public class FileAccessI implements Serializable{ g[G+s4Nv
n_~u!Ky_P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 BD.&K_AW
RandomAccessFile oSavedFile; arK(dg~S
long nPos; 3Z0ez?p+5
4,g_$)
RE._Ov>
public FileAccessI() throws IOException z }3`9
{ t@X{qm:%Z
this("",0); 8'WoG]E_
} r:{;HM+
oYx4+xH/
Ml,~@} p
public FileAccessI(String sName,long nPos) throws IOException --OAsbr
{ ^8.s"4{
oSavedFile = new RandomAccessFile(sName,"rw"); h`i*~${yg
this.nPos = nPos; n4XEyCrD
oSavedFile.seek(nPos); u@]rR&h`
} b=@H5XTZyK
w{8O$4 w
g)dKXsy(F
public synchronized int write(byte[] b,int nStart,int nLen) rX(Ol,&oP
{ E!A+J63zsw
int n = -1; c1tM(]&
try{ >o:y.2yCe
oSavedFile.write(b,nStart,nLen); KWS\iu
n = nLen; (usFT_
} Y{KN:|i.!
catch(IOException e) QLxe1[qI
{ D :)HKD.
e.printStackTrace (); FPb4VJ|xm
} lvOM1I
s4uZ>
<) cJz
return n; &?@gCVNO,
} [L>mrHqG
r\A|fiL
(N6=+dNY
} C>A} e6o
qrHCr:~
A&N$=9.N1
/* GvzaLEo
**SiteInfoBean.java B/Js>R
*/ 0VnRtLnqI
package NetFox; ZAJ~Tbm[f
kfY. 9$(d
xLdkeuL[%
public class SiteInfoBean { %MCJ%Ph
lLur.f
f4O}WU}l{s
private String sSiteURL; //Site's URL g-pEt#
private String sFilePath; //Saved File's Path |F4)&xN\
private String sFileName; //Saved File's Name !_q=r[D\
private int nSplitter; //Count of Splited Downloading File &E]<KbVx
}0[<xo>K
lFp:F5
public SiteInfoBean() I)\{?LdHR
{//nSplitter的缺省值为5 v4qpE!W27~
//default value of nSplitter is 5 :x,dYJm
this("","","",5); dUQ)&Hv
} %H[~V f?d
e/uLBZ
}#q0K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DzbcLg%:W
{ `z^50Vh|
sSiteURL= sURL; !q~f;&rg
sFilePath = sPath; 1! j^
sFileName = sName; hzk4SOT(
this.nSplitter = nSpiltter; xyP0haE
},=ORIB B:
u+9)B 6O1
} 6<%b}q9Mo
~Qd|.T
au E8 ^|
public String getSSiteURL() ,V9r2QY
{ HXN. ,[
return sSiteURL; vA{DF{S4
} }tW1\@ =
!gL1
G?^w <
public void setSSiteURL(String value) z5_jx&^Z
{ \j<aFOT(
sSiteURL = value; : sG/
} ujn7DBE"
6P T)
a$EudD#+
public String getSFilePath() r]'[qaP
{ |.b&\
return sFilePath; nf-6[dg
} Y>{%,d#s_
E#A}2|7,g
[s+FX5'K
public void setSFilePath(String value) _&N:%;9uD
{ *Z+U}QhHD6
sFilePath = value; , {}S<^?]
} |kF"p~s
5s%FHa
8.&P4u i
public String getSFileName() /!_FE+
{ J|@O4g
return sFileName; )h]tKYx
} /uPMzl
#3O$B*gV6
&gP1=P,!
public void setSFileName(String value) ;Za^).=
{ 9 ge'Mo
sFileName = value; lmIphOUoIw
} u`XZtF<vf
gk}.LE
LWxP}? =
public int getNSplitter() 7CCSG{k
{ a *bc#!e
return nSplitter; |}: D_TX
} [fJxbr"
+jN)$Y3Ya
z<s~`
public void setNSplitter(int nCount) 7H)tF&
{ ?IDkDv!na~
nSplitter = nCount; DG=_E\"#
} ;m:I
} qL$\[(
!95Q4WH-@
3W[Ps?G
/* +3pfBE|
**Utility.java MnQ 6 !1Z
*/ ]>0$l _V
package NetFox; >w1jfpQ@t$
;p"#ZS7
<^+&A7Q-_
public class Utility { VoyRB2t
M2A3]wd2a
oMxpdG3y-
public Utility() S,s") )A1
{ Va/}|&9
C@MJn)$4
D7v.Xq|
} wh3Wuh?x
h m(
//线程睡眠 $wcV~'fM
public static void sleep(int nSecond) 9Z:pss@
{ W,%qL6qV
try{ zB"y^g
Thread.sleep(nSecond); "9RW<+
} Zf?jnDA
catch(Exception e) ZO\bCrk
{ (DM8PtZg
e.printStackTrace (); 2~)q080jh
} _2<k,Dl;RY
} P!/:yWd
UFE~6"t(
//日志 I^QB`%v5
public static void log(String sMsg) 'fIG$tr9X
{ AVp"<Uv
System.err.println(sMsg); ?o(Y\YJf
} I -XkxDw
,`(Qs7)Xx
yiczRex%rq
public static void log(int sMsg) Zk #C!]=
{ ]r1Lr{7^S
System.err.println(sMsg); Y2>*' nU
} ?nozB|*>ut
} )1&,khd/u
SU4~x0
AH ]L C6-
/* 8=3$U+
**TestMethod.java rzKn5Z
*/ a@-!,Hi
package NetFox; e)4L}a
jAD{?/RB}
HF%)ip+
public class TestMethod { (<yQA. M
o&E2ds3
<-|g>
public TestMethod() j2:A@a6
{ ///xx/weblogic60b2_win.exe i^/D_L.
try{ zQx7qx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); WtbOm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); YifTC-Q;
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1<f,>BQ+
fileFetch.start(); ^^(4xHN
} Xx=.;FYk
catch(Exception e){e.printStackTrace ();} GnW_^$Fs
-KCQ!0\F
V7>{,
} <V*M%YWs
;<v9i#K5
oFS)3.
public static void main(String[] args) Z9lfd6MU,
{ OSCeTkR
new TestMethod(); MtK5>mhZI`
} -MeO|HWm
} 0Yc#fD
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