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)); e\~l!f'z
} {8ECNQ[]
for(int i=0;i<nEndPos.length-1;i++) Uh\]?G[G
{ ;o >WXw
nEndPos = nStartPos[i+1]; @ta?&Qf)
} 6z]`7`G
nEndPos[nEndPos.length-1] = nFileLength; 1NGyaI
} ~'[jBn)
} 3M$X:$b
X2P``YFV{
{_as!5l
//启动子线程 b_ JWnh
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I{<;;;a
for(int i=0;i<nStartPos.length;i++) F '#^`G9
{ uRGB/ju^E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *+~D+_,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;o%:7&
nStartPos,nEndPos,i); "GLYyC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J=P;W2L
fileSplitterFetch.start(); 6JWGu/A
} D1! {S7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b_mWu@$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k-]xSKG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y&3TQ]f\
nEndPos = " + nFileLength); -3`Isv
// fileSplitterFetch[nPos.length-1].start(); V7n >,k5
uOb2npPj
voH4
//等待子线程结束 4)E|&)-fu8
//int count = 0; &*ZC0V3
//是否结束while循环 #!Ze\fOC
boolean breakWhile = false; -Y2&A$cM
Q~h6J*
ny~W]1
while(!bStop) pr)K{~m]{<
{ oX#9RW/ >I
write_nPos(); { $X X
Utility.sleep(500); !rz)bd3$
breakWhile = true; @F~0p5I
Q{8qm<0g
?U$}Rsk{#
for(int i=0;i<nStartPos.length;i++) bt0djJRw
{ U* 4{"
if(!fileSplitterFetch.bDownOver) *|sxa#
{ xdCs5ko
breakWhile = false; U~Xf=f_Q$
break; bD d_}
} $}V7(wu 6@
} I>d I[U
if(breakWhile) #fO*ROe
break; ~.iA`${y%
2(hvv-
l#p}{
//count++; |x*{fXdMhr
//if(count>4) dG"K/|
// siteStop(); _F3KFQ4,S-
} K*0aXr?
d\\r_bGW
S!u6dz^[$X
System.err.println("文件下载结束！"); dD:
} 9/FG,9
catch(Exception e){e.printStackTrace ();} keqr%:E8
} :EYu 4Y
yi sF5`+
xGwTk
//获得文件长度 poTl|y @
public long getFileSize() bkxk i@t
{ ?rky6
int nFileLength = -1; ]Jja
try{ vU?b"n
URL url = new URL(siteInfoBean.getSSiteURL()); GJ.kkTMT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OiYNH~hv
httpConnection.setRequestProperty("User-Agent","NetFox"); P\Ai|"=&]
~6\& y
nMTLD
int responseCode=httpConnection.getResponseCode(); \FIa,5k8
if(responseCode>=400) Gv!BB=ir(
{ #4Dn@Gqh.Y
processErrorCode(responseCode); |if~i;VKL
return -2; //-2 represent access is error w:ORmR.p
} KuIBYaK, g
<j{0!J@:
w/?nUp
String sHeader; aytq4Ts
X!HDj<
q-A`/9
for(int i=1;;i++) fEx+gQW_
{ <jpeu^7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Rrh<mo(yj#
//Utility.log(in.readLine()); m(8jSGV
sHeader=httpConnection.getHeaderFieldKey(i); cBg,k[,
if(sHeader!=null) JZWgr&O<
{ (y-x01H
if(sHeader.equals("Content-Length")) <WZ1-
{ -q'xC:m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x:!C(Ep)
break; SPfD2%jjC
} &oon'q5;
} T@%;0Ro~
else R;0W+!fE
break; ZMdM_i?
} UOn!Y@
} 7(yXsVq
catch(IOException e){e.printStackTrace ();} }f<fgY
catch(Exception e){e.printStackTrace ();} [?Mc4uT{
+vSCR(n
6{b%Jfo
Utility.log(nFileLength); Wv6z%r<
CPc"
,`ZPtnH+
return nFileLength; X_vI0YX9
} 3*CzXK>`M&
7JxE|G
#[gcg]6c
//保存下载信息（文件指针位置） B rez&3[
private void write_nPos() [$hptQv
{ ~a|^?7@p
try{ ZAI1p+
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2neF<H?^o
output.writeInt(nStartPos.length); >P<k[vF
for(int i=0;i<nStartPos.length;i++) Ymwx(Pm
{ Sf+(1_^`t
// output.writeLong(nPos); zF[3%qZE:T
output.writeLong(fileSplitterFetch.nStartPos); 4]Un=?)I
output.writeLong(fileSplitterFetch.nEndPos); Paae-EmC
} U@o2gjGN
output.close(); OVDMC4K2z!
} :6 Hxxh
catch(IOException e){e.printStackTrace ();} o8~f
catch(Exception e){e.printStackTrace ();} I ybl;u
} &*jxI[
dAu^{1+2
Q\&AlV
//读取保存的下载信息（文件指针位置） ki[;ZmQqY
private void read_nPos() r~S!<9f
{ mp&Le YYn
try{ w,M1`RsK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JxX jDYrU
int nCount = input.readInt(); 0C7thl{Dms
nStartPos = new long[nCount]; ;']vY
nEndPos = new long[nCount]; .fio<mqi
for(int i=0;i<nStartPos.length;i++) n4ds;N3Hd
{ X";QA":
nStartPos = input.readLong(); ^yn[QWFO
nEndPos = input.readLong(); '0'"k2"vC
} hW0,5>[7%
input.close(); Ff)~clIK '
} H3 A]m~=3
catch(IOException e){e.printStackTrace ();} C$N4
catch(Exception e){e.printStackTrace ();} [oQ`HX1g
} /7UovKKbz
q;1VF;<"vH
oiTMP`Y
private void processErrorCode(int nErrorCode) )z?&"I
{ 902!M65[rG
System.err.println("Error Code : " + nErrorCode); +Op%,,Db
} >)AE|j`
/tId#/Y
Ev$-PX
//停止文件下载 ;[WSf{k
public void siteStop() O4b-A3:
{ 9E->;0-
bStop = true; <2o.,2?G
for(int i=0;i<nStartPos.length;i++) g(@$uJ
fileSplitterFetch.splitterStop(); X]+(c_i:hC
*sc0,'0
f^[{k {t
} bMK#^ZoH
} =\ti<
//负责部分文件的抓取 "6I-]:K-
**FileSplitterFetch.java P-E'cb%ub
*/ h-?q6O/|
package NetFox; 0I(GB;E
(/9.+V_
aIn)']
import java.io.*; 4y]:Gqz~
import java.net.*; 'b=eC
<tu[cA>
]AFM Y<mB
public class FileSplitterFetch extends Thread { /VhE<}OtH
_Cv[`e.
MrKU,-
String sURL; //File URL |mQtjo
long nStartPos; //File Snippet Start Position :o.x=c B
long nEndPos; //File Snippet End Position <6}f2^
int nThreadID; //Thread's ID ZZ]OR;8
boolean bDownOver = false; //Downing is over @MlU!oR&
boolean bStop = false; //Stop identical <WHs
FileAccessI fileAccessI = null; //File Access interface "a0u-}/D
~kSnXJv
f}9PEpa,Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ig.6[5a\
{ .^)C:XiW
this.sURL = sURL; LAK-!!0X
this.nStartPos = nStart; @??c<]9F
this.nEndPos = nEnd; ^?K?\
nThreadID = id; 2d>d(^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :YRzI(4J
} U!;aM*67
"dLMBY~
lkSz7dr@
public void run() ,/w852|ub
{ u]]5p[|S
while(nStartPos < nEndPos && !bStop) Oc"'ay(g
{ :~0^ib<v;
9(N)MT5F
li3PR$W V
try{ v'bd.eqw
URL url = new URL(sURL); "zeJ4f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {-v\&w
httpConnection.setRequestProperty("User-Agent","NetFox"); >jrz;r
String sProperty = "bytes="+nStartPos+"-"; Vhbj.eX.)
httpConnection.setRequestProperty("RANGE",sProperty); x^='pEt{
Utility.log(sProperty); [:R P9r}
q~g&hR}K
[!dnm1
InputStream input = httpConnection.getInputStream(); +SuUI-.
//logResponseHead(httpConnection); yZ?_q$4kEI
|S>J<]H p
cO=UswIkwO
byte[] b = new byte[1024]; 8x^H<y=O
int nRead; %)6:eIS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zfr(dQ
{ 3R:7bex
nStartPos += fileAccessI.write(b,0,nRead); QqFfR#
//if(nThreadID == 1) xV n]m9i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !s[j1=y
} 6(<~1{ X%
]=86[A-2N
UTK.tg
Utility.log("Thread " + nThreadID + " is over!"); ;qVEI/
bDownOver = true; "-j@GCme
//nPos = fileAccessI.write (b,0,nRead); I3zitI;
} ,QHx*~9
catch(Exception e){e.printStackTrace ();} M#lVPXS
} 5rHnU<H@y
} &J&w4"0N'
'/yx_RK2?
\")YKN=W
//打印回应的头信息 v4k=NH+w
public void logResponseHead(HttpURLConnection con) 0JZq:hUd
{ Bn#HJ17/#
for(int i=1;;i++) ]N(zom_0d
{ Dpp52UnTE
String header=con.getHeaderFieldKey(i); Ng;b!S
if(header!=null) ?D )qgH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1TxhEXB
Utility.log(header+" : "+con.getHeaderField(header)); AZ]SRz9mKY
else ]-s`#
break; _9O }d
} 4Utx 9^
} #;*ai\6>vD
A^Hp#b@
9 K /
public void splitterStop() %wjU^Urya
{ TNPGw!
bStop = true; FO'. a
} ZV<y=F*~f
M4hN#0("4
%CE@}
} o2e h)rtB
Ko]h r
tv=FFfQ
/* E?q'|f
**FileAccess.java 1'U%7#;E
*//文件访问(定位，写) 98%tws`
package NetFox; (B/F6 X;o.
import java.io.*; IO&#)Ft
,cO)Sxj
g-V\s&}
public class FileAccessI implements Serializable{ dBq,O%$oq
2|NyAtPb5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QsF<=b~
RandomAccessFile oSavedFile; \FY De
long nPos; XOU-8;d
x#gmliF
AO7qs:+
public FileAccessI() throws IOException oJp_c
{ (PrPH/$
this("",0); <ZvPtW
} BLH3$*,H
,l?76g
fUWm7>6VA>
public FileAccessI(String sName,long nPos) throws IOException G-i_s6Wu
{ a5~C:EU0
oSavedFile = new RandomAccessFile(sName,"rw"); AA& dZjz
this.nPos = nPos; +VW]%6+
oSavedFile.seek(nPos); 2Ku#j ('
} N8(x),
.Zt/e>K&
/sC[5G%
public synchronized int write(byte[] b,int nStart,int nLen) v*]Xur6e}
{ YK+Z0ry
int n = -1; .6/p4OR|
try{ |2&mvjk@H
oSavedFile.write(b,nStart,nLen); gLxyRbVI
n = nLen; hE#8_34%s
} rHdP4:n
catch(IOException e) WI4_4
{ S"A_TH
e.printStackTrace (); .p0n\$r
} d\Z4?@T<5
lRK?%~
sF3 l##Wv
return n; @dKf]&h%%
} }N9a!,{P=b
]~M{@h!<
ziGL4c0p
} l45F*v]^
i&Cqw~.H
tJ_@AcF
/* n$0)gKN7
**SiteInfoBean.java z'K7J'(R
*/ G}xBYc0b
package NetFox; N)y;owgo
K:50?r_-6
%t|2GIu
public class SiteInfoBean { zw9ULQ$#
;S27m]Q?
XN%D`tbvJ
private String sSiteURL; //Site's URL 3:Egqw
private String sFilePath; //Saved File's Path $/#)
private String sFileName; //Saved File's Name uOUw8
private int nSplitter; //Count of Splited Downloading File CrX-?$
?iO^b.'I#
7IW7'klkvD
public SiteInfoBean() \mit&EUh}
{//nSplitter的缺省值为5 A_ z:^9
//default value of nSplitter is 5 ,^66`C[G
this("","","",5); ywtDz8!^u
} +Ws}a
EMH}VigR
tl^;iE!-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .z7f_KX^
{ [c%}L 3B
sSiteURL= sURL; GuDD7~qxY
sFilePath = sPath; 'N/%SRk
sFileName = sName; uHh2>Px
this.nSplitter = nSpiltter; -xEg"dY/
mYRR==iDL
r~a}B.pj
} [/^g) ^s:
^w}Ib']X
o"CqVRR
public String getSSiteURL() yf>,oNIAg
{ w8Vzx8
return sSiteURL; md_s2d
} \aRB
;G&O"S><]c
RaqrVC
public void setSSiteURL(String value) {lw ec"{
{ udr'~,R
sSiteURL = value; U.)eJ1a
} u-cC}DP
tXGcwoOB
> _) a7%
public String getSFilePath() \05C'z3]
{ KA[Su0
return sFilePath; 8u23@?
} ]qQB+]WN
Fd0FG A&L
,FPgs0rrS
public void setSFilePath(String value) cW>`Z:6{K
{ :9>nY
sFilePath = value; a[#BlH
} tjL#?j
wQ95tN
yZ6X$I:C
public String getSFileName() PSvRO%&
{ nI` 1@vB&
return sFileName; @72G*u\Wz
} Jx,s.Z0@7,
VAz+J
!1]xKNp]
public void setSFileName(String value) eVJL|uI|
{ P=g+6-1
sFileName = value; KJ |1zCM
} *V+fRN4 W
!b Km}1T
<Z wEdq
public int getNSplitter() yw^,@'
{ _z<q9:
return nSplitter; Cr"hu;
} svII =JB
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.- o,_eg1f
public void setNSplitter(int nCount) p_5+L@%Gb
{ B!lw>rUMQ
nSplitter = nCount; >m46tfoM
} 06r cW `
} IrK )N
ENr&k(>0HQ
e hGC N=
/* :DP{YL|x
**Utility.java QX/`s3N
*/ Y"U&3e,
package NetFox; 3J{'|3x
z5zm,Jw
n$K_KU v
public class Utility { $~l:l[Zs
\>Q,AyL
ZGBcy}U(k
public Utility() _=p|"~rN$
{ gqamGLK
_;+&'=6.[
:2+:(^l
} owB)+
pQJZE7S
//线程睡眠 W@LR!EW)
public static void sleep(int nSecond) @A%`\Ea%
{ iWEYSi\)n
try{ `W=JX2I
Thread.sleep(nSecond); 5VS<I\o}
} R8]bi|e)
catch(Exception e) t `oP;
{ ]y/:#^M+
e.printStackTrace (); %r!-*p<i|
} <7+.5iB3
} ewR0e.g
bL<cgtz7)
//日志 [DviN
public static void log(String sMsg) mE1*F'0a
{ .FyC4"b=c
System.err.println(sMsg); U/;Vge8{
} 1>LquZ+Kj
scmbDaOn
-rBj-4|"
public static void log(int sMsg) c_i;'
{ _`_$UMK;
System.err.println(sMsg); od>.5{o
} XooAL0w
} z'o+3zq^
p;HZA}p \
6\L,L&
/* VEk|lX;2
**TestMethod.java .)Q'j94Q
*/ >jIc/yEYKI
package NetFox; e~1??k.;=
Z~ (QV0}
j&r5oD;
public class TestMethod { ofV{SeD67
^B7Aam
)deuB5kz
public TestMethod() (uE_mEIsv
{ ///xx/weblogic60b2_win.exe yWy9IWI["
try{ }_S]!AWz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E^G=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .#SWfAb2h
SiteFileFetch fileFetch = new SiteFileFetch(bean); +|N"i~f>j
fileFetch.start(); rx<fjA%
} xo}hu%XL
catch(Exception e){e.printStackTrace ();} +Aq}BjD#
te_D ,
.$rcTZ
} B7 T+a
W#$rC<Jh]
asb")NfIm
public static void main(String[] args) R[6&{&E:
{ sSxra!tv4
new TestMethod(); wiZK-#\x
} {chl+au*l
} g~]FI
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