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)); PxE3K-S)G
} \|ao`MMaD<
for(int i=0;i<nEndPos.length-1;i++) v.ui!|c
{ bu"!jHPB
nEndPos = nStartPos[i+1]; 0|b>I!_"g
} &VcV$8k
nEndPos[nEndPos.length-1] = nFileLength; ]+$?u&0?w
} W}1 ;Z(.*
} bJ;'`sw1
;UP$yM;
UY2OZ&&
//启动子线程 2Hv+W-6v
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yiI1x*^
for(int i=0;i<nStartPos.length;i++) m#F`] {
{ &t-kpA|EG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ---N9I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f V(J|
nStartPos,nEndPos,i); YnP5i#"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cs'{5!i]
fileSplitterFetch.start(); wa3}SB
} uM'Jp?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hq 188<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .GcKa024
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", as_PoCoss
nEndPos = " + nFileLength); C6y&#uX\
// fileSplitterFetch[nPos.length-1].start(); eR"<33{
;({W#Wa
Z(!\%mn
//等待子线程结束 @ry_nKr9
//int count = 0; ]g&TKm
//是否结束while循环 1'\/,Es
boolean breakWhile = false; IaXeRq?<
.6'qoo_N
O7IJ%_A&
while(!bStop) alvrh'51
{ 6K<K
write_nPos(); Tu7QCr5*
Utility.sleep(500); v}Fr@0%
breakWhile = true; JO<wU
"w.3Q96r
ia 73?*mXT
for(int i=0;i<nStartPos.length;i++) 3%ZOKb"D*
{ *=c1do%F
if(!fileSplitterFetch.bDownOver) RdML3E
{ ;d9QAN&0}
breakWhile = false; baK$L;Xo:
break; #Vha7
} I.k *GW
} b>N8F^}~O
if(breakWhile) uRr o?m<
break; 4_cqT/
0_t`%l=
UZsH9 o
//count++; IobD3:D8W
//if(count>4) :Zz '1C
// siteStop(); \K!VNB>h
} xK\d4"
e@OX_t_
9 |vLwQ
System.err.println("文件下载结束！"); \} :PLCKT
} 5o8EC" 0
catch(Exception e){e.printStackTrace ();} %1$,Vs<RH
} > "=>3
J6aef^>
& 9 ?\b7
//获得文件长度 [1 9,&]z
public long getFileSize() 2('HvH]k
{ Hg$lXtn]
int nFileLength = -1; qeZ? 7#Gf
try{ 46&/gehr
URL url = new URL(siteInfoBean.getSSiteURL()); NPe%F+X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <HVt V9R
httpConnection.setRequestProperty("User-Agent","NetFox"); Tyf`j,=
7VFLJrt
YVanW
int responseCode=httpConnection.getResponseCode(); 'ub@]ru|
if(responseCode>=400) $'hEz/
{ :A'y+MnK<
processErrorCode(responseCode); ';=O 0)u
return -2; //-2 represent access is error '(L7;+E
} pD#rnp>WWt
.UY^oR=b{
M1iS(x
String sHeader; )f<z%:I+Z
m-"w0Rl1T
3x'|]Ns
for(int i=1;;i++) W]5w \
{ *itUWpNhr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^RtIh-Z.9
//Utility.log(in.readLine()); b?QoS|<e?
sHeader=httpConnection.getHeaderFieldKey(i); ^qD$z=z-
if(sHeader!=null) |2n4QBH!
{ Y\?"WGL)p
if(sHeader.equals("Content-Length")) >e[i5
{ K}MK<2vU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <;Zmjeb+#
break; (rm?jDm
} I75DUJqy]
} &AbNWtCV+G
else *.d)OOpLo
break; \Et3|Iv
} (S\[Y9
} zsyIV!(
catch(IOException e){e.printStackTrace ();} #KexvP&*
catch(Exception e){e.printStackTrace ();} orMwAV
aH/ k Ua
k5.Lna
Utility.log(nFileLength); X))/ m[_[
<s<n
S2GxV/E
return nFileLength; p xa*'h"b^
} GH:jH]u!V
]R f[y
*VhL\IjN]
//保存下载信息（文件指针位置） MJ [m
private void write_nPos() "Nbq#w\
{ A1>OY^p3%
try{ 70tH:Z)"
output = new DataOutputStream(new FileOutputStream(tmpFile)); {dMsz
output.writeInt(nStartPos.length); qwgPk9l
for(int i=0;i<nStartPos.length;i++) CxOob1@
{ dufu|BL|}
// output.writeLong(nPos); Ata:^qI
output.writeLong(fileSplitterFetch.nStartPos); UJ7*j%XQz_
output.writeLong(fileSplitterFetch.nEndPos); %oa-WmWm
} *Y7u'v
output.close(); tm RXgTS
} k],Q9
catch(IOException e){e.printStackTrace ();} rgtT~$S
catch(Exception e){e.printStackTrace ();} =BAW[%1b
} ryUQU^v
Tc`=f'pP)4
peuZ&yK+"
//读取保存的下载信息（文件指针位置） jc[Y}gd,
private void read_nPos() V/ uP%'cd
{ '3DXPR^B6
try{ iYm-tsER;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .P%bkD6M
int nCount = input.readInt(); YdC6k?tzS
nStartPos = new long[nCount]; F]]]y5t
nEndPos = new long[nCount]; q"sed]
for(int i=0;i<nStartPos.length;i++) -g Sa_8R
{ %JD,$pPs
nStartPos = input.readLong(); 9YQb&
nEndPos = input.readLong(); ^{;oM^Q'
} Z|j>gq
input.close(); e95Lo+:f
} <?}-$
catch(IOException e){e.printStackTrace ();} &LZn FR
catch(Exception e){e.printStackTrace ();} {xB!EQ"
} s.N/2F&*W
Tc &z:
(U_ujPD ?
private void processErrorCode(int nErrorCode) .A{tQ1&_
{ QIvVcfM^
System.err.println("Error Code : " + nErrorCode); {e9@-
} JZ*/,|1}EC
BmMGx8P
u9GQU
//停止文件下载 L<-_1!wh
public void siteStop() )<;Y-u.UW
{ Eog0TQ+*
bStop = true; )E@.!Ut4o
for(int i=0;i<nStartPos.length;i++) JNYFD8J~
fileSplitterFetch.splitterStop(); z] PSpUd
}mq6]ZrK
dIa+K?INX
} xU>WEm2
} " H&W}N
//负责部分文件的抓取 \lf;P?M^
**FileSplitterFetch.java #9}D4i.`}
*/ m^f0V2M_
package NetFox; ?o4C;
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pW@Pt 3u
import java.io.*; JG!mc7
import java.net.*; Cc' 37~6~P
8\ +T8(m
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public class FileSplitterFetch extends Thread { YYl4"l
K&ZtRRDd
$i}y8nlQ
String sURL; //File URL RJ ||}5
long nStartPos; //File Snippet Start Position aS{n8P6vW
long nEndPos; //File Snippet End Position K>r,(zgVc
int nThreadID; //Thread's ID &(G\[RWp\
boolean bDownOver = false; //Downing is over ]J}
boolean bStop = false; //Stop identical 3kIN~/<R+7
FileAccessI fileAccessI = null; //File Access interface zH4D8@[7O
"9P>a=Y
_jI,)sr4ic
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException AOWmzu{zw
{ zRl3KjET
this.sURL = sURL; :W:K:lk
this.nStartPos = nStart; k_qd|
this.nEndPos = nEnd; B=yqW
nThreadID = id; N^ds RYC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V>)OpvoT#
} H*QIB_
Vb4#,
o]` *M|
public void run() djQH1^(IU
{ I<4Pur>"
while(nStartPos < nEndPos && !bStop) oMD>Ywc-
{ /-ch`u md
/vde2.|
w%VU/6~
try{ HU}7zK2
URL url = new URL(sURL); _ Yx]_Y9I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YTX,cj#D^&
httpConnection.setRequestProperty("User-Agent","NetFox"); kg~mgMR+w
String sProperty = "bytes="+nStartPos+"-"; ./k/KSR
httpConnection.setRequestProperty("RANGE",sProperty); @ ZwvBH
Utility.log(sProperty); =wHVsdNCN
Zq|I,l0+E
wd^':
InputStream input = httpConnection.getInputStream(); ;%5N%0,
//logResponseHead(httpConnection); YTpSHpf@
ia~HQ$'+n
KB,j7 ~V
byte[] b = new byte[1024]; OwUhdiG
int nRead; 5\sd3<:+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +L|?~p`V
{ M~#gRAUJ
nStartPos += fileAccessI.write(b,0,nRead); Xe'x[(l
//if(nThreadID == 1) bv9]\qC]T<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }[};IqVaK
} ^qvbqfh
yZ(zdM\/sL
gQelD6c
Utility.log("Thread " + nThreadID + " is over!"); ?|C2*?hZ+
bDownOver = true; H8^(GUhyp
//nPos = fileAccessI.write (b,0,nRead); eRstD>r
} uk]$#TV*q>
catch(Exception e){e.printStackTrace ();} vnt%XU,,Y
} 5 +YH.4R
} cLJ$M`e
nQtWvT
R'`qKc
//打印回应的头信息 Oo8VeRZ
public void logResponseHead(HttpURLConnection con) &yTqZ*Yuk
{ p* (JjH
for(int i=1;;i++) Lpz>>}
{ S6M}WR^,
String header=con.getHeaderFieldKey(i); mPK:R^RjG&
if(header!=null) o>i4CCU+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B6As,)RjD:
Utility.log(header+" : "+con.getHeaderField(header)); 4*#18<u5
else qI9z;_,gNz
break; K5VWt)Z#
} m6K}|j
} 6NuD4Ga
S_4?K)n #
,~$p,ALwN7
public void splitterStop() (sTpmQx,b
{ Y>T-af49
bStop = true; GPv1fearl
} GL0L!="!
bMu+TgAT,
vHc%z$-d
} @#>rYAb8,
YQ)kRhFA
c(m<h+2VL
/* 1 ~*7f>
**FileAccess.java ]BZA:dd.G
*//文件访问(定位，写) q[ZTHd.-
package NetFox; &|ex`nwc0
import java.io.*; y0.'?6k
z}9(x.I
A_ZY=jP
public class FileAccessI implements Serializable{ ww3-^v
z`}qkbvi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1;8UC;,
RandomAccessFile oSavedFile; S-b/S5
long nPos; dNH08q8P
g\:[ 55;8
1~`fVg
public FileAccessI() throws IOException `pS9_NYZ}
{ EhvX)s
this("",0); \<>ih)J@tt
} 7wqK>Y1a
[`[|l
#&k5d:
public FileAccessI(String sName,long nPos) throws IOException JPUW6e07o
{ a:`E0}C
oSavedFile = new RandomAccessFile(sName,"rw"); 8z`G,qh
this.nPos = nPos; A#<?4&
oSavedFile.seek(nPos); V>LwqS~`
} RnE4<Cy
w<3#1/g!2B
gp?uHKsM
public synchronized int write(byte[] b,int nStart,int nLen) 6ex/TySM
{ : /N0!&7
int n = -1; 9};8?mucr
try{ yu|8_<bq
oSavedFile.write(b,nStart,nLen); $G+@_'
n = nLen; EjR9JUu
} (D&3G;0tK
catch(IOException e) 0<@KG8@hI;
{ YnMvl
e.printStackTrace (); RJ&RTo
} lh7#t#
?4&e;83_#y
vWv"
return n; rfJz8uF%
} $6 9&O
,Vm < rK
hH3RP{'=
} h"Q8b}$^)
b3[!V{|
!hy-L_wL]
/* q!7ANib6O
**SiteInfoBean.java ]|ag
*/ A,<E\
package NetFox; fOGFq1D
P>D)7V9Hh
Pn1^NUMZJ
public class SiteInfoBean { #A/
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$GcqBg-Hi
private String sSiteURL; //Site's URL ]p GL`ge5
private String sFilePath; //Saved File's Path q`7PhA
private String sFileName; //Saved File's Name :\c ^*K(9
private int nSplitter; //Count of Splited Downloading File ie95rZp
p27~>xQ
P|E| $)m
public SiteInfoBean() rJ4S%6w
{//nSplitter的缺省值为5 FVbb2Y?R
//default value of nSplitter is 5 f~R(D0@
this("","","",5); s^9Voi.y
} Y\P8v
I;(L%TT `
1n8/r}q'H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [l??A3G
{ H$t_Xw==
sSiteURL= sURL; &PHTpkaam
sFilePath = sPath; ;xj?z\=Pg
sFileName = sName; |SSSH
this.nSplitter = nSpiltter; /C:gKy4
s!zx} 5
G>}255qY
} .2t4tb(SUw
L`TLgH&?R
U'_Q>k
public String getSSiteURL() ET*SB
{ Of#u
return sSiteURL; ~,Ix0h+H+M
} 4F:\-O
K@]4g49A/j
T&bYa`f]
public void setSSiteURL(String value) Dml;#'IF3
{ #:_Kws>+
sSiteURL = value; G~a ZJ,
} {}przrU^c
&Z@o Q
RbnVL$c
public String getSFilePath() N>`Aw^ _@&
{ +Kc
return sFilePath; CK@@HSm}l
} WpP}stam/
V f&zL Sgr
"HIRTE;&
public void setSFilePath(String value) sll\g
{ Z5n1@a__
sFilePath = value; %[TR^Th6
} :3Ox~o
|HQW0
M|h3Wt~7
public String getSFileName() ;$|nrwhy
{ "&u@d~`-n
return sFileName; H*R"ntI?w
} Bsvr?|L\
IEi^kJflU
uGGt\.$]s
public void setSFileName(String value) C}Cs8eUn
{ =UQ3HQD
sFileName = value; Btn?N
} + &Eqk
2%m BK
ES7s1O$#
public int getNSplitter() wn%A4-%{
{ ~36!?&eA8
return nSplitter; 1GcE)e!>
} tyFzSrfc
J*M>6Q.)
rb.N~
public void setNSplitter(int nCount) kTgEd]^&D
{ _`T_">9r
nSplitter = nCount; =:pJ
} v!5 `|\
} XRi8Gpg
A;M'LM-M
CD~.z7,LC
/* Svmy(w~m
**Utility.java $U~]=.n
*/ 0GeTSFj
package NetFox; 7{*>agQh
#*Ctwl,T
wIt}dc
public class Utility { F]&*ow
(!WD1w
Q;rX;p^W
public Utility() "chDg(jMZ
{ Wne@<+mX
^1.By^ $
5\nAeP
} R\[e!g*I
sPIn|d
//线程睡眠 ;i+jJ4
public static void sleep(int nSecond) b>ySv
{ z2GY:<s
try{ =Xr.'(U
Thread.sleep(nSecond); 1yhDrpm
} Dlvz)
catch(Exception e) s$j,9uRr
{ |+9&rAg
e.printStackTrace (); dy[X3jQB
} YT,{E,U;
} d2$IH#~9B
OneY_<*a<
//日志 Q=$2c[Uk
public static void log(String sMsg) J|73.&B
{ >hIu2jm
System.err.println(sMsg); &};zvo~P.
} +NUG
nxFBID
eHUOU>&P]
public static void log(int sMsg) kAUymds;O
{ f!X[c?Xy"
System.err.println(sMsg); !4+<<(B=E
} 1'Dai`
} p!%pP}I
OjA,]Gv6
CqC`8fD1
/* 9\(| D#
**TestMethod.java Q3?F(ER@
*/ p]c%f2E>d
package NetFox; ;O,jUiQ
hhvyf^o
4*;MJ[|
public class TestMethod { K|=A:
I&5!=kR
m1AJ{cs
public TestMethod() {)<v&'*c~
{ ///xx/weblogic60b2_win.exe Ow,b^|
try{ *oix6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Aos+dP5h,8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #/37V2E
SiteFileFetch fileFetch = new SiteFileFetch(bean); $*m-R*kt
fileFetch.start(); YS_;OFsd
} ^iYj[~
catch(Exception e){e.printStackTrace ();} Wd ELV3
*LY8D<:zs
f|(M.U-
} 9>#6*/Oa7
zm;C\s rF
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public static void main(String[] args) |y!A&d=xYn
{ Flb&B1
new TestMethod(); Znv,9-
} %&bY]w
} 3G4-^hY<
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