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)); sAS\-c'6
} PIP2(-{ai
for(int i=0;i<nEndPos.length-1;i++) SiHZco I
{ g<oSTAw
nEndPos = nStartPos[i+1]; y]eH@:MJ;A
} hfP}+on%
nEndPos[nEndPos.length-1] = nFileLength; W|~Lmdzj
} msg&~"Z
} &O5%6Sv3d
~Bn#AkL
" M8j?
//启动子线程 /HH5Mn*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (qHI>3tpY
for(int i=0;i<nStartPos.length;i++) n5"rSgUtE
{ 2-nL2f!a{p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %YefTk8cr,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'wz*GMGWC
nStartPos,nEndPos,i); D8slSX`6j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O-:#Q(H!
fileSplitterFetch.start(); yJ8WYQQMG
} ftsr-3!Vm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -tZ2 N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PH97O`"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a_'W1ek-@
nEndPos = " + nFileLength); q5:-?|jXJ
// fileSplitterFetch[nPos.length-1].start(); \^SL Zhe
a^i`DrX
/Q5pAn-u
//等待子线程结束 -wlob`3
//int count = 0; =UA-&x@
//是否结束while循环 i{PRjkR
boolean breakWhile = false; g;w4:k)U
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bmna*!l^M
while(!bStop) V| z|H$-
{ !cT#G
write_nPos(); N5csq(
Utility.sleep(500); YFOK%7K
breakWhile = true; -QCo]:cp
1t=Y+|vA9
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for(int i=0;i<nStartPos.length;i++) p#'BV'0bl
{ s0v?*GRX
if(!fileSplitterFetch.bDownOver) ~\DC )
{ z~+_sTu
breakWhile = false; wA) NB
break; j2deb`GD
} 6'395x_.\
} ,7SLc+
if(breakWhile) g1muT.W]S
break; 3G8BYP
DzO0V"+H}k
cEi{+rfZd|
//count++; W&}YMb
//if(count>4) V=k!&xN~
// siteStop(); ui`xgR\6Rh
} %Nd|VAe
qfvd(w
8qp!S1Qnv
System.err.println("文件下载结束！"); 1F-o3\
} k=H{gt
catch(Exception e){e.printStackTrace ();} |~hSK
} *RUB`tEL
?2OT:/I,
|uV1S^!A
//获得文件长度 a)PBC{I
public long getFileSize() )-|A|1Uo
{ V\%;S
int nFileLength = -1; f!e8xDfA
try{ #>O,w0<qM
URL url = new URL(siteInfoBean.getSSiteURL()); \`jFy[(Pa'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #nX0xV5=
httpConnection.setRequestProperty("User-Agent","NetFox"); _)p@;vGV
n_AW0i.
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int responseCode=httpConnection.getResponseCode(); s ,\w00-:
if(responseCode>=400) Hs~M!eK
{ _Akc7"
processErrorCode(responseCode); ,ZV<o!\
return -2; //-2 represent access is error l!Z>QE`.S
} 4O9HoX#-?
7xB#)o53
gl:vJD
String sHeader; T,Cq;|g5E
t#MU2b
c)#b*k,lw<
for(int i=1;;i++) B~-VGT2o
{ 468LVe?0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?RiW:TQ*
//Utility.log(in.readLine()); +cheLc
sHeader=httpConnection.getHeaderFieldKey(i); 5&v'aiWK
if(sHeader!=null) tz j]c
{ B@e,3:
if(sHeader.equals("Content-Length")) *58<.L|
{ })g|r9=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |;6FhDW+'
break; ?0hk~8c
} 5|NM]8^^0[
} l Vo](#W
else LPb43
break; FT/H~|Z>
} r.xGvo{iY
} Vm_y,;/(-R
catch(IOException e){e.printStackTrace ();} c~ l$_A
catch(Exception e){e.printStackTrace ();} cz OhSbmc
N~EM`d
ss T o?WL|
Utility.log(nFileLength); EyI 9$@4
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!w]!\H
return nFileLength; *y5d&4G2
} &E.0!BuqV
*W y0hnr;]
U|g4t=@ZR
//保存下载信息（文件指针位置） &at>pV3_
private void write_nPos() t<$9!"
{ ($7>\"+Tl
try{ PkF B.
output = new DataOutputStream(new FileOutputStream(tmpFile)); M7Cq)cT
output.writeInt(nStartPos.length); :35J<oG
for(int i=0;i<nStartPos.length;i++) [esjR`u
{ ?(*KQ#d
// output.writeLong(nPos); @7 &rDZ
output.writeLong(fileSplitterFetch.nStartPos); {F6hx9?
output.writeLong(fileSplitterFetch.nEndPos); 5b0Ipg
} Ko\m8\3?fK
output.close(); 7~C@x+1S/
} .=3Sm%
catch(IOException e){e.printStackTrace ();} K7M7T5<
catch(Exception e){e.printStackTrace ();} ScQJsFE6
} g % q7
ppN96-]^0
|q^e&M<
//读取保存的下载信息（文件指针位置） 6aK'%K
private void read_nPos() a^iefwsNc
{ RQy|W}d_
try{ ;dRTr *
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?=_l=dR
int nCount = input.readInt(); ppR~e*rv-
nStartPos = new long[nCount]; OQ 5{#
nEndPos = new long[nCount]; 1{_tV^3@
for(int i=0;i<nStartPos.length;i++) fxI>FhU_
{ .ZxSJ"Rk
nStartPos = input.readLong(); ;.V5:,&
nEndPos = input.readLong(); KNC!T@O|{#
} <po.:c Ce
input.close(); `XP]y=
} _Z#yI/5r
catch(IOException e){e.printStackTrace ();} Os*,@N3t
catch(Exception e){e.printStackTrace ();} yi"V'Us
} {{ R/:-6?@
*oY59Yf
?q7VB
private void processErrorCode(int nErrorCode) t2BkQ8vr
{ {O5;V/00}
System.err.println("Error Code : " + nErrorCode); f6PXcV
} *hF5cM[
McNj TD
zbddn4bW9
//停止文件下载 $d:/cN 8E
public void siteStop() {ogGi/8
{ VHM,W]
bStop = true; |n=m8X
for(int i=0;i<nStartPos.length;i++) p!AQ
fileSplitterFetch.splitterStop(); 2!~j(_TA
B*zb0hdo:
{}D8Y_=9\
} Q6_!I42Y`
} nrUrMnlg
//负责部分文件的抓取 9^4^EY#
**FileSplitterFetch.java 58mzh82+
*/ N1\u~%AT"
package NetFox; \x(J vDt
d5T0#ue/e
|ZJ]`qmZ
import java.io.*; +VdYT6{p
import java.net.*; )Y\},O
#h/-
16keCG\
public class FileSplitterFetch extends Thread { J}i$ny_3OB
rxI?|}4
8|dlt$
String sURL; //File URL j08G-_Gjn
long nStartPos; //File Snippet Start Position FnP/NoZa>
long nEndPos; //File Snippet End Position uB 6`e!Q
int nThreadID; //Thread's ID tJUMLn?
boolean bDownOver = false; //Downing is over U/&?rY^|
boolean bStop = false; //Stop identical TA`*]*O(
FileAccessI fileAccessI = null; //File Access interface GTYGm
D(~6h,=m
*=MC+4E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8/-GrdyE
{ \kzxt/Ow
this.sURL = sURL; G( nT.\
this.nStartPos = nStart; I=D`:u\H
this.nEndPos = nEnd; > 9JzYI^
nThreadID = id; _Eq:Qbw#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BpDf4)|
} yh]#V"W3
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public void run() *Mg=IEu-6[
{ bV@53_)N2
while(nStartPos < nEndPos && !bStop) ,`P,))
{ A0oC*/
6}L[7~1
+C/K@:p
try{ *VIM!/YW
URL url = new URL(sURL); e l'^9K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .<u<!fL2
httpConnection.setRequestProperty("User-Agent","NetFox"); _66zXfM<
String sProperty = "bytes="+nStartPos+"-"; =k2+VI
httpConnection.setRequestProperty("RANGE",sProperty); zIH[ :
Utility.log(sProperty); :?@d\c'
+{]/ b%P
HzQ6KYAMq
InputStream input = httpConnection.getInputStream(); @-qxNw
//logResponseHead(httpConnection); oE"!
n1y#gC
Z!G;q}zZ!
byte[] b = new byte[1024]; GaSk&'n$Y
int nRead; +TpM7QaL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w{F8]N>0<
{ cGsP0LkHC
nStartPos += fileAccessI.write(b,0,nRead); cP$b>3O
//if(nThreadID == 1) G&/}P$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8$v17 3
} P;MS%32
fk*JoR.o
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Utility.log("Thread " + nThreadID + " is over!"); ^-~.L: }q
bDownOver = true; .Ky<9h.K
//nPos = fileAccessI.write (b,0,nRead); fT[6Cw5w`
} gO*cX&
catch(Exception e){e.printStackTrace ();} qnrf%rS
} &I:X[=;g
} Gd%6lab
6\\B{%3R2
> :!faWX
//打印回应的头信息 z\_q`43U7
public void logResponseHead(HttpURLConnection con) $SG^, !!&A
{ qq[2h~6P]
for(int i=1;;i++) }!Qo wG
{ Tx/
String header=con.getHeaderFieldKey(i); Ca@[]-_H
if(header!=null) -R~;E[ {%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +3si=x\=/
Utility.log(header+" : "+con.getHeaderField(header)); [5)1 4% x
else '3[Ecy#
break; dI>)4()
} SN?jxQ
} Tl8S|Rg
NvJu)gI%
z|+L>O-8
public void splitterStop() o7/_a/
{ 7g
bStop = true; m?;)C~[
} |]+m<Dpyr2
Arir=q^2
0Hff/~J
} H",yVD
73Mh65
x:xKlPGd
/* Ad@))o2
**FileAccess.java F8_pwJUpf-
*//文件访问(定位，写) P%'bSx1
package NetFox; "!E(=W?
import java.io.*; n_$lRX5
?tqTG2!(
r5lp<md
public class FileAccessI implements Serializable{ DXSZ#^,S[W
;NLL?6~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L9fhe,en
RandomAccessFile oSavedFile; H!Uy4L~>
long nPos; 2?QIK3"v
U QXT&w
.X_k[l9
public FileAccessI() throws IOException .g(yTA
{ e<~uU9 lg1
this("",0); }`5%2iG
} HY5g>wv@
(}4tj4d
\dIIZSN
public FileAccessI(String sName,long nPos) throws IOException "h$A.S
{ Bq79Ev .-
oSavedFile = new RandomAccessFile(sName,"rw"); 8@6:UR.)
this.nPos = nPos; mEz&:A
oSavedFile.seek(nPos); j,6dGb
} q$:T<mFK$
nHD4J;l
tq<7BO<6
public synchronized int write(byte[] b,int nStart,int nLen) W>wE8? _,
{ 6/nhz6=
int n = -1; <G2;nvRr
try{ 3t68cdFlz
oSavedFile.write(b,nStart,nLen); 2~R"3c+^
n = nLen; Z(/jQ=ozQ
} vB/MnEKR
catch(IOException e) ua`2 &;T=
{ e{To&gy~
e.printStackTrace (); E^A9u |x
} +c}fDrr)
;OPzT9
ws?p2$Cla
return n; }(op;7
} g3LAi#m
N=tyaS(YJ
+s1+;VUs3
} /LuwPM
jTSw0\}
TeHL=\L-^
/* lG%oqxJ+ L
**SiteInfoBean.java o\b8lwA,
*/ CN\s,. ]
package NetFox; .H7"nt^
{r[*}Bv
WZ6!VE{
public class SiteInfoBean { g B+cU
Z%(aBz7Et
RUX!(Xw
private String sSiteURL; //Site's URL h!yF
private String sFilePath; //Saved File's Path 7" Dw4}T
private String sFileName; //Saved File's Name FT`y3~
private int nSplitter; //Count of Splited Downloading File Ug3PZ7lK
-Zocu<Rs
;#`Z(A}
public SiteInfoBean() f7d)
{//nSplitter的缺省值为5 Sh2q#7hf
//default value of nSplitter is 5 >,uof?
this("","","",5); Xw9,O8}C7
} e)!X9><J
]~3wq[O
zHDC8m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9OF5A<%"u
{ "^22Y}VB
sSiteURL= sURL; ;\4}Hcg
sFilePath = sPath; 5xTm]
sFileName = sName; _V-@95fK
this.nSplitter = nSpiltter; ;[gv-H
+Nc|cj
(;~[}"
} s8@fZ4
Be8Gx
@8n0GCv
public String getSSiteURL() Tk.MtIs)V}
{ Q}\,7l
return sSiteURL; ?o9l{4~g
} _f^q!tP&d
=Q3Go8b4HJ
r;upJbSX
public void setSSiteURL(String value) o=;.RYi
{ $AG.<
sSiteURL = value; gqZ7Pro.
} uZd)o AB
;)"r^M)):
MSRIG-
public String getSFilePath() -Ah\a0z
{ 3w!oJB
return sFilePath; wpx,~`&
} )z7.S"U
P63z8^y
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public void setSFilePath(String value) g>OGh o
{ k?|VFh1
sFilePath = value; ScZ$&n
} f=}u;^
;u}MG3Y8
oJyC{G
public String getSFileName() X=${`n%LG
{ c7wza/r>
return sFileName; P,I3E?! j
} uZ<Bfrc
~g1@-)zYxK
Qbt fKn95
public void setSFileName(String value) |])%yRAGQ
{ m_\CK5T_
sFileName = value; rUx%2O|qu
} 3Y=T8Gi#
OjrQ[`(E
Y<a/(`
public int getNSplitter() ^6J*yV%
{ [h%_`8z
return nSplitter; {'>X6:
} 9Ki86
.}Bb :*@
-cY/M~
public void setNSplitter(int nCount) 0A5xG&
{ "=4=Q\0PT
nSplitter = nCount; 'DntZK
} 0vQkm<
} "]zq<LmX
@OwU[\6fc}
,!sAr;Rk`
/* 2HQHC]
**Utility.java [>C^ 0\Z~
*/ ag|d_;
package NetFox; mI0|lp 1$
ks(PH6:]<
pSV 8!
public class Utility { z81I2?v[Jr
BtU,1`El5
r~t&;yRv
public Utility() 4XX21<yn
{ M7jDV|Go
R8":1 #&
c!w4N5aM
} !ZSC"
wx<5*8zP
//线程睡眠 LjxTRtB_
public static void sleep(int nSecond) F\,3z7s
{ Y`lC4*g
try{ MzJ5_}
Thread.sleep(nSecond); "uZ'oN
} 8&dmH&
catch(Exception e) 0Apvuf1
{ M{O2O(
e.printStackTrace (); v[F_r
} {(xNC#
} Ai#W. n
#-e3m/>
//日志 8&`s wu&
public static void log(String sMsg) j}0*`[c
{ <`6-J `.
System.err.println(sMsg); joM98H@
} K;[V`)d'
fFSW\4JD=
OP:;?Fs9`
public static void log(int sMsg) tb0s+rb
{ 9H.E15B
System.err.println(sMsg); u7a4taM$d
} 9%\q*
} ;h
BMFpkK9|
I"<~!krt%
/* ps<JKHC/c
**TestMethod.java |mmIu_
*/ ?P"ht
package NetFox; m;Sw`nw?
3=;iC6 `
W-Hw%bwN/q
public class TestMethod { VZ_4B *D
J5|Dduv
o^DiIoor
public TestMethod() yDy3;*lE
{ ///xx/weblogic60b2_win.exe wW!*"z
try{ 0 w@~ynW[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2!&:V]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9O}YtX2
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,YH^jc
fileFetch.start(); p1X lni%=
} Ev$?c9*>
catch(Exception e){e.printStackTrace ();} \Sm.]=br
[lyB@) 6.
<V>vDno\
} tYmWze.j
S~Nx;sB
<niHJ*
public static void main(String[] args) '%K,A-7W
{ L & PhABZ
new TestMethod(); LuQ=i`eXx
} /!7m@P|&D
} B;7L:
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