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)); fbl8:c)I
} qI]PM9
for(int i=0;i<nEndPos.length-1;i++) uG5RE
{ YmBo/IM
nEndPos = nStartPos[i+1]; ]+U:8*
} )A@ }mIs"
nEndPos[nEndPos.length-1] = nFileLength; Ok0zgi
} NmH1*w<A
} g6s&nH`Z2
@Cnn8Y&'
{OH @z!+d
//启动子线程 !Q/%N#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s8r|48I#;
for(int i=0;i<nStartPos.length;i++) G{ |0}
{ +t9$*i9`L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B%]yLJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A:-MRhE9X
nStartPos,nEndPos,i); nnzfKn:J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jfLkp>2E'
fileSplitterFetch.start(); |D@/4B1P
} fZq_]1(/uP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B-R& v8F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "k;j@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )}Vb+
nEndPos = " + nFileLength); Bql5=p
// fileSplitterFetch[nPos.length-1].start(); ]j4Nl?5*x
K)D5%?D
B}:/2?gQ
//等待子线程结束 $!'S7;*uW
//int count = 0; `4xnM`:L"
//是否结束while循环 Wzn!BgxRr
boolean breakWhile = false; JU6PBY~C'
UY ^dFbJ
_,"?R]MO
while(!bStop) )335X wA+
{ b0PQ;?R#V
write_nPos(); vp[;rDsIJ$
Utility.sleep(500); LR(Q.x
breakWhile = true; TKwMgC}<[
a?d)lnk
5xS ze;
for(int i=0;i<nStartPos.length;i++) $i|c6&
{ O<*l"fw3
if(!fileSplitterFetch.bDownOver) b`9J1p.;
{ ,k9@%{4 l
breakWhile = false; (G E)
break; u|G&CV#r
} vqeWt[W v
} 7U3b YU~;
if(breakWhile) 9Kpzj43
break; 1"hd5a
hoj('P2a#n
|}?o=bO
//count++; CnXl 7"
//if(count>4) ,/bSa/x`
// siteStop(); bG|aQ2HW
} odPdWV,&*
]Qu.-F#g
WGK:XfOBQ
System.err.println("文件下载结束！"); !{WIN%O
} (V06cb*42[
catch(Exception e){e.printStackTrace ();} San=E@3}v!
} sC< B
}C'H@:/
nt5x[xa
//获得文件长度 m|CB')
public long getFileSize() u2FD@Xq?
{ 0afDqvrC6
int nFileLength = -1; z_ 01*O
try{ YF4?3K0F:k
URL url = new URL(siteInfoBean.getSSiteURL()); #s}cK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {hNvCk
httpConnection.setRequestProperty("User-Agent","NetFox"); (C&Lpt_
%XQ!>BeE
d3IMQ_k
int responseCode=httpConnection.getResponseCode(); 2_i9 q>I
if(responseCode>=400) liuw!
{ yu~o9
processErrorCode(responseCode); AeZ__X
return -2; //-2 represent access is error /uNgftj
} W5f|#{&L:
~vGX(8N
Eq\PSa=gz
String sHeader; .boBo$f
6^Q/D7U;s
rgK:ujzW!
for(int i=1;;i++) `"-ln'nw
{ \y^Ho1Fj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p$:ERI
//Utility.log(in.readLine()); SKUri
sHeader=httpConnection.getHeaderFieldKey(i); Il8,g+W]
if(sHeader!=null) $Ith8p~
{ P@xb
if(sHeader.equals("Content-Length")) \\D(St
{ .^F(&c*['
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?RMOy$L
break; HT% =o}y
} nF)XZB0F
} *}@zxFe+
else 01_*^iCf5
break; CD"D^\z
} O,c}T7A'?w
} ;Pd nE~
catch(IOException e){e.printStackTrace ();} &hSABtr}
catch(Exception e){e.printStackTrace ();} )*CDufRFz
[dXpz^Co
^tr?y??k
Utility.log(nFileLength); C-:lM1
HO`N]AMw
CC~:z/4,N
return nFileLength; wr~Ydmsf
} *?o`90HHP[
c?/R=/H
|n/qJIE6
//保存下载信息（文件指针位置） !%lcn O
private void write_nPos() oLh2:c
{ _[:>!ekx
try{ "gQ-{ W
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]E:K8E
output.writeInt(nStartPos.length); 3$yOv"`
for(int i=0;i<nStartPos.length;i++) ~ZuFMVR
{ fp)%Cr
// output.writeLong(nPos); [J-uvxD
output.writeLong(fileSplitterFetch.nStartPos); +5k^-
output.writeLong(fileSplitterFetch.nEndPos); |Q\O% cb
} VUF$,F9
output.close(); h't!1u
} 4[P]+Z5b+
catch(IOException e){e.printStackTrace ();} <8,,pOb
catch(Exception e){e.printStackTrace ();} qtI42u{
} )/vse5EG+
Ig{ 3>vB
"rJJ~[Y
//读取保存的下载信息（文件指针位置） x&4gy%b
private void read_nPos() 7+Z%#G~T
{ g)M"Cx.
try{ hUo}n>Aa
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >69-[#P!
int nCount = input.readInt(); 5Kw$QJ/
nStartPos = new long[nCount]; }NgevsV>;
nEndPos = new long[nCount]; Jjr&+Q^3Tu
for(int i=0;i<nStartPos.length;i++) n]Z() "D
{ KccIYn~
nStartPos = input.readLong(); ~5@bWJ
nEndPos = input.readLong(); AW')*{/(Ii
} Gkr?M^@K
input.close(); cmu|d
} H-g CY|W
catch(IOException e){e.printStackTrace ();} [(kC/W)!
catch(Exception e){e.printStackTrace ();} M. o}?
} L8WYxJ k
t8:QK9|1
/qwl;_Jcf
private void processErrorCode(int nErrorCode) IJQ" *;
{ E/:mO~1< c
System.err.println("Error Code : " + nErrorCode); xJ(}?0h-X
} xro%AM
ZdsYIRU#
@GyxOc@6
//停止文件下载 ~^<1k-
public void siteStop() I8%Uyap{
{ $eU oFa5A
bStop = true; 5BAGIO<w
for(int i=0;i<nStartPos.length;i++) pj9*$.{
fileSplitterFetch.splitterStop(); +v{g'
|J^}BXW'^)
wOLA8UYW
} ^NB\[ &
} R[vA%G
//负责部分文件的抓取 - xE%`X
**FileSplitterFetch.java Po*G/RKu4W
*/ ?? 2x*l1
package NetFox; E-v#G~
AQU^7O
N/V~>UJ0{*
import java.io.*; HD~o]l=H
import java.net.*; L}hc|(:
Gzw9E.Hk
^/M-*U8ab
public class FileSplitterFetch extends Thread { l+XTn;cS
sogdM{tz\
6cVJu%<V
String sURL; //File URL jV 982Y
long nStartPos; //File Snippet Start Position [~Vj(H=KwI
long nEndPos; //File Snippet End Position $Le|4Hj
int nThreadID; //Thread's ID J-U5_>S
boolean bDownOver = false; //Downing is over (ptk!u6
boolean bStop = false; //Stop identical &peUC n
FileAccessI fileAccessI = null; //File Access interface /BQB7vL
A8T75?lL(
MY w3+B+Jj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2AdO
{ AA &>6JB{
this.sURL = sURL; 1@<PcQBp
this.nStartPos = nStart; s%/x3anz=
this.nEndPos = nEnd; L}Rsg'U
nThreadID = id; {Lg]chJq?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;%a
} r>,s-T!7
f=T-4Of
w,!IvDCAw
public void run() Y2d(HD@
{ m4_ZGjmJM
while(nStartPos < nEndPos && !bStop) ~Iz{@Ep*
{ nmWo:ox4;(
AO~f=GW
k%Wj+\93f
try{ EC`=nGF
URL url = new URL(sURL); -PiakX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MG-#p8
httpConnection.setRequestProperty("User-Agent","NetFox"); 8k_cC$*Ng
String sProperty = "bytes="+nStartPos+"-"; p6AF16*f0
httpConnection.setRequestProperty("RANGE",sProperty); i}=n6
Utility.log(sProperty); von<I
,vcd>"PK
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InputStream input = httpConnection.getInputStream(); wmDO^}>ZP
//logResponseHead(httpConnection); 59#o+qo4
_uq[D`=
:x[SV^fw[
byte[] b = new byte[1024]; 'B9q&k%<
int nRead; 5#U=x ,7e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k{C03=xk
{ zFm:=,9
nStartPos += fileAccessI.write(b,0,nRead); " 7g\X$
//if(nThreadID == 1) 1)t*l;.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B*OBXN>'P
} wO&+Bb\=
F S!D
*nx$r[Mqj
Utility.log("Thread " + nThreadID + " is over!"); V{C{y5
bDownOver = true; 5*\]F}
//nPos = fileAccessI.write (b,0,nRead); t|?eNKVV9'
} V: n\skM
catch(Exception e){e.printStackTrace ();} d=eIsP'h
} ni?5h5-
} C17$qdV/
4vJg"*?
C+%6N@
//打印回应的头信息 PrhGp _5
public void logResponseHead(HttpURLConnection con) _^@>I8ix
{ ["WWaCcx
for(int i=1;;i++) U28frRa
{ "_ H9]}Q
String header=con.getHeaderFieldKey(i); T!X`"rI
if(header!=null) +!cibTQTT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1b,MJ~g$
Utility.log(header+" : "+con.getHeaderField(header)); w&x$RP
else >Vph_98|
break; `5 Iaz
} #pnB+h&tE
} KD`*[.tT
R q`j|tY
G]zyx"0Sqb
public void splitterStop() j1O_Az|3
{ "0aJE1)p:
bStop = true; oH;9s-Be
} 5pH6]$
u$<>8aMei
ZVz`g]
} Eg(.L,dj
6PT"9vR`)
I~Q G
/* <.=-9O6
**FileAccess.java bKt4
*//文件访问(定位，写) I9L7,~s
package NetFox; )x3p7t)#
import java.io.*; W!V-m
]([^(&2
bD`h/jYv
public class FileAccessI implements Serializable{ }"M5"?
n;LjKE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a FL;E
RandomAccessFile oSavedFile; H,EGB8E2
long nPos; PZihC
F^CR$L& K
t!\B6!Fo
public FileAccessI() throws IOException &3 *#h
{ r"!xI
this("",0); <UwYI_OX
} 6 IRa$h>H
{a0yHy$H
IXpn(vX
public FileAccessI(String sName,long nPos) throws IOException Zp/$:ny
{ 3z% W5[E)
oSavedFile = new RandomAccessFile(sName,"rw"); `(M0I!t
this.nPos = nPos; 3fxcH
oSavedFile.seek(nPos); IZBY*kr
} Y+{jG(rg.F
=wlPm5
1D1qOg"LE
public synchronized int write(byte[] b,int nStart,int nLen) fZb}-
{ Gn^m541
int n = -1; $"ACg!=M
try{ ;tC$O~X
oSavedFile.write(b,nStart,nLen); JHa\"h
n = nLen; :,V&P_
} Jwpc8MQ
catch(IOException e) %+oqAYm+s
{ Hu+GN3`sx^
e.printStackTrace (); $f=6>Kn|^]
} sGx3O i
!~tf0aY
iKu4s
return n; w+$~ds
} 4UHviuOo8
B.:1fT7lI
z9E*1B+
} <R?S
u.Tknw-X
s8dP=_ `
/* EHK+qrym
**SiteInfoBean.java :LCyxLI
*/ {DZ xK(
package NetFox; P!I Lji!
Q/0oe())
]QGo(+
public class SiteInfoBean { \1hQ7:f;\
g3 Oro}wt6
={;7WB$
private String sSiteURL; //Site's URL QD-`jV3
private String sFilePath; //Saved File's Path _9'hmej
private String sFileName; //Saved File's Name qWJHb Dd
private int nSplitter; //Count of Splited Downloading File V''fmWo7
|g'ceG-
3H|drj:KV
public SiteInfoBean() FKUo^F?z
{//nSplitter的缺省值为5 BjGfUQ
//default value of nSplitter is 5 q:=jv6T#
this("","","",5); Dus!Ki~8(t
} 0lV;bVa%
Mh MXn;VKj
HPg%v|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N`~f77G
{ F\^\,hy
sSiteURL= sURL; ^7yaMB!
sFilePath = sPath; hkdF
sFileName = sName; FY`t7_Y?GV
this.nSplitter = nSpiltter; +X`&VO6~
R{ udV
Tv6y+l
} 9bhubx\^/
(\o4 c0UzK
=R"LB}>h}
public String getSSiteURL() P@D\5}*6
{ = 5[%%Lf
return sSiteURL; nw_s:
} UyFC\vQ
4sW'pH
u%lUi2P2E
public void setSSiteURL(String value) kP'm$+1or
{ p:W{c/tV
sSiteURL = value; 5nTcd@lX
} !a25cm5ys
\XwC|[%P
!2>@:CKX
public String getSFilePath() B&_Z&H=
{ I0qJr2[X~
return sFilePath; I1rB,%p
} ;&'ryYrex
.FV^hrJxI;
4LW~
public void setSFilePath(String value) 9tb-;|
{ bZr,jLEf
sFilePath = value; ?1zGs2Qs
} ^;F5ymb3U
+25=u|#4r
e-OKv#]
public String getSFileName() 1z0|uc
{ kKjcW` [
return sFileName; iSUu3Yv,_m
} UWhJkJsX
'IT]VRObP
~ch%mI~
public void setSFileName(String value) ,fqM>Q
{ L62%s[
sFileName = value; K|OPtYeb
} z 2jC48~
Ftd,dqd
9|[uie
public int getNSplitter() bub6{MQW8e
{ zG8g}FrzG;
return nSplitter; z"mpwmv5
} Go^TTL
><>%;HZ
\q3ui}-9
public void setNSplitter(int nCount) *A4eYHn@
{ [S8*b^t4
nSplitter = nCount; MT:VQ>fC
} UO#`Ak
} qVI0?B x
W/b)OlG"2
La3rX
/* k{=dV
**Utility.java +S[3HX7H
*/ .gzfaxi
package NetFox; ``I[1cC
MJrPI a[pN
U^BM5b
public class Utility { #HW<@E
vU5}E\Ny
(CgvI*O
public Utility() bar=^V)
{ 8ZqLGa]
3Zl:rYD?
I8`$a
} %4Qs|CM)m
*,%$l+\h
//线程睡眠 u`.)O2)xU
public static void sleep(int nSecond) gujP{Z
{ &xhwOgI#,
try{ ZO%iyc%
Thread.sleep(nSecond); Hb::;[bm:
} iRlpNsN
catch(Exception e) }ijQ*ECdl
{ )J0h\ky
e.printStackTrace (); Cl!(F6K*
} %?aq1 =B
} 2H0BNrYM
<<E9MIn_
//日志 EU>`$M&w-
public static void log(String sMsg) ^]'_Qbi]}
{ esQ$.L
System.err.println(sMsg); "tl$JbRTY
} t*-cX
x#N_h0[i
M8<Vd1-5
public static void log(int sMsg) J=gFiBw
{ >C!^%e;m
System.err.println(sMsg); @SpP"/)JY
} ZTz07Jt
} |FM*1Q[1
<Z<meB[g
a'/i/@h
/* u%+k\/Scp.
**TestMethod.java hjM?D`5x
*/ Hh*?[-&r~
package NetFox; xE]y*\
yz=X{p1
\q4r/SbgW
public class TestMethod { ' |B3@9<
<F(2D<d{;)
N$IA~)
public TestMethod() *B}O
{ ///xx/weblogic60b2_win.exe 3 V>$H\H
try{ H,5]w\R6\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qIQRl1Tw;V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n*A1x8tn
SiteFileFetch fileFetch = new SiteFileFetch(bean); _oCNrjt9
fileFetch.start(); {\%I;2X
} XD|g G
catch(Exception e){e.printStackTrace ();} x: _[R{B
|*UB/8C^/!
u4w!SD
} z\A ),;
S#v3%)R
YzQ1c~+
public static void main(String[] args) |\?u-O3
{ $--+M D29Q
new TestMethod(); 5B4/2q=
} X~c?C-fV
} %Q0R] Hg
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