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)); mQ`atFz:Z
} t[2b~peNI
for(int i=0;i<nEndPos.length-1;i++) %WU=Vy4
{ -sA&1n"W&5
nEndPos = nStartPos[i+1]; 2gO@
} :N<Qk
nEndPos[nEndPos.length-1] = nFileLength; 8WV5'cX
} `WH$rx!
} 82,^Pu
*~P| ? D'
?S& yF
//启动子线程 T`@brL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s~Ivq+ipr;
for(int i=0;i<nStartPos.length;i++) k5K5OpY
{ qZ!kVrmg&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NB<8M!X/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), l/(~Kf9eQG
nStartPos,nEndPos,i); OD7A(28
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KC}G_"f.$
fileSplitterFetch.start(); rrfJs
} Io<T'K
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~/A2:}Cp=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >QYx9`x&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k(RKAFjY
nEndPos = " + nFileLength); Sydl[c pH$
// fileSplitterFetch[nPos.length-1].start(); GpTZp#~;
Mhn1-ma:
Z{vc6oj
//等待子线程结束 5yt=~
//int count = 0; &i3SB[|
//是否结束while循环 O1jiD_Y!9
boolean breakWhile = false; .*6NqX$
&iu]M=Yb
.s4vJKK0
while(!bStop) 3}V (8
{ >|RoLV
write_nPos(); KsIHJr7-
Utility.sleep(500); i?d545. u
breakWhile = true; dpE^BWv3
,5<AV K-#Q
qGN>a[D
for(int i=0;i<nStartPos.length;i++) v(Kj6'
{ 8fi'"
if(!fileSplitterFetch.bDownOver) .s"Og;g
{ v(0ujfSR0
breakWhile = false; D"$ 97
break; 2?LPr
} aC'6
} c]1AM)xo
if(breakWhile) eN5F@isy
break; ~pH!.|k-&
A#']e8
_l] 0V g`
//count++; ;uc3_J]
//if(count>4) eu)""l
// siteStop(); :I/9j=@1
} J*K=tA
lmUCrs37
POc<XLZB
System.err.println("文件下载结束！"); ze9n}oN
} W\0u[IV.x
catch(Exception e){e.printStackTrace ();} ,>qtnwvlHP
} 0iC5,
q},,[t
<#"_Qgdix
//获得文件长度 JXww_e[
public long getFileSize() 6)=;cc{Vr
{ =d@)*W 6
int nFileLength = -1; T>*G1-J#
try{ ^h=gaNL
URL url = new URL(siteInfoBean.getSSiteURL()); SJc*Rl>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D|$0~1y
httpConnection.setRequestProperty("User-Agent","NetFox"); [V8^}s}tF
$L|+Z>x
jp}.W
int responseCode=httpConnection.getResponseCode(); HC/a
if(responseCode>=400) +3AX1o%p,#
{ B k\KG
processErrorCode(responseCode); 8?'=Aeo
return -2; //-2 represent access is error !jEV75
} h)W#
IcqzMmb
vd^Z^cpip
String sHeader; )BaGY
FB,rQ9D
xi<}n#
for(int i=1;;i++) H,EZ% Gl
{ Kx[+$Qt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WHjJR
//Utility.log(in.readLine()); DuAix)#FN9
sHeader=httpConnection.getHeaderFieldKey(i); yO\bVu5V
if(sHeader!=null) ghkV^ [
{ Q>\DM'{:4
if(sHeader.equals("Content-Length")) Mw+ l>92
{ i8cmT+}>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Kn?h
break; Xa"I
} (VCJn<@@
} cFjD*r-
else j+lcj&V#
break; >#T?]5Z'MF
} ?mVSc/
} d}?KPJ{
catch(IOException e){e.printStackTrace ();} +uNMyVH
catch(Exception e){e.printStackTrace ();} nemC-4}
!-SI &qy
g38MF
Utility.log(nFileLength); Mbly-l{|
v$;URF%^
?c_:S]^
return nFileLength; .UN?Ak*R
} &`]T#">
K1;b4Sl?A
ZRr.kN+F
//保存下载信息（文件指针位置） Sq2 8=1%
private void write_nPos() JnQ@uZb`
{ i_!$bk<yo
try{ pma=*
output = new DataOutputStream(new FileOutputStream(tmpFile)); v}!^RW'X
output.writeInt(nStartPos.length); v`qXb$YW
for(int i=0;i<nStartPos.length;i++) ET*:iioP
{ S]e;p\8$Z
// output.writeLong(nPos); Oq}7q!H
output.writeLong(fileSplitterFetch.nStartPos); ~xJr|_,gp
output.writeLong(fileSplitterFetch.nEndPos); (\ |Go-2G
} x'Nc}
output.close(); xj]^<oi<
} BuitM|k'
catch(IOException e){e.printStackTrace ();} J'&K
catch(Exception e){e.printStackTrace ();} nF,zWr[x
} }1a(*s,s-^
e!k4Ij-]
T#H-GOY:
//读取保存的下载信息（文件指针位置） Wrm3U/>e
private void read_nPos() au+:-Khm
{ zf\$T,t)
try{ &!+1GI9z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x%dVD
int nCount = input.readInt(); &EC8{.7
nStartPos = new long[nCount]; y"_rDj`
nEndPos = new long[nCount]; p~-)6)We?
for(int i=0;i<nStartPos.length;i++) $P #KL//
{ *~UK5Brf1
nStartPos = input.readLong(); Nk$|nn9#'
nEndPos = input.readLong(); 6>'>BamX
} }Os7[4RW
input.close(); ?'tFTh
} wjKc!iB
catch(IOException e){e.printStackTrace ();} po*r14f
catch(Exception e){e.printStackTrace ();} (;N#Gqb6l
} u3jLe=Y'\
7VLn$q]:
3)(uC+?[
private void processErrorCode(int nErrorCode) [E9_ZdBT
{ ftV~!r
System.err.println("Error Code : " + nErrorCode); R0q|{5S
} [|C
^*,?x
@G|z_
//停止文件下载 MJn=
public void siteStop() 4Ub7T=LG
{ pA\"Xe&
bStop = true; SU.$bsu
for(int i=0;i<nStartPos.length;i++) 6x16?x
fileSplitterFetch.splitterStop(); GCxmqoQ
k+eeVy
?nM]eUAP
} QC1\Sn/
} @8cn<+"b
//负责部分文件的抓取 H 9?txNea
**FileSplitterFetch.java 7aHP;X~0
*/ Ed#Hilk'
package NetFox; T>5N$i
YizwKcuZ
}l5Q0'
import java.io.*; ;a(7%
import java.net.*; [3v&j_
,,h>_IA
-]:1zU
public class FileSplitterFetch extends Thread { K/!>[d
o"qG'\x
9*(uJA
String sURL; //File URL af=lzKt*
long nStartPos; //File Snippet Start Position $KsB'BZy
long nEndPos; //File Snippet End Position GP=bp_L
int nThreadID; //Thread's ID 0BP=SCi
boolean bDownOver = false; //Downing is over rxeOT# N}
boolean bStop = false; //Stop identical wqJ1^>TB
FileAccessI fileAccessI = null; //File Access interface wHs4~"EY9
+ ;B K|([#
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %eJE@$
{ .R&jRtb/E
this.sURL = sURL; F441K,I
this.nStartPos = nStart; TcH7!fUj
this.nEndPos = nEnd; 88zK)k{
nThreadID = id; "X-"uIc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O?Qi
} H `_{n<
if+97^Oy
xsx0ZovhY
public void run() h?vt6t9
{ E~`<n]{G-C
while(nStartPos < nEndPos && !bStop) #mRT>]di`D
{ o_.`&Q6n
Yo,n#<37
F>aaUj
try{ bDV/$@p
URL url = new URL(sURL); DhiIKd9W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f<Yg_TG
httpConnection.setRequestProperty("User-Agent","NetFox"); =la~D]T*g
String sProperty = "bytes="+nStartPos+"-"; Q&&oP:4~X*
httpConnection.setRequestProperty("RANGE",sProperty); -\8v{ry
Utility.log(sProperty); #6 M3BF
%"AB\lL.
6FEIQ#`{
InputStream input = httpConnection.getInputStream(); TL: 6Pe
//logResponseHead(httpConnection); P:m6:F@hO
)/BbASO$)Z
)8V=!73
byte[] b = new byte[1024]; KH9D},
int nRead; ]=(PtzVa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jJe?pT]o
{ J|DY /v
nStartPos += fileAccessI.write(b,0,nRead); 1"RC!
//if(nThreadID == 1) :E2 ww`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'E4}++\
} @"/:Omh
'~AR|8q?
g ?{o2gG
Utility.log("Thread " + nThreadID + " is over!"); ??,/85lM
bDownOver = true; B[;aNyd<
//nPos = fileAccessI.write (b,0,nRead); u56WB9Z
} %G'P!xQhy
catch(Exception e){e.printStackTrace ();} M[7$F&&n
} $)VnHr `hy
} !OMl-:KUzE
b}Xh|0`b+
6sNw#pqh
//打印回应的头信息 sQMfU{S /
public void logResponseHead(HttpURLConnection con) B$_-1^L e
{ Uh3N#O
for(int i=1;;i++) [s~6,wz
{ #E4|@}30`
String header=con.getHeaderFieldKey(i); P$&l1Mp
if(header!=null) O@`KGZEPY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]+T$D
Utility.log(header+" : "+con.getHeaderField(header)); F+<Z%KuCu
else YGOhUT |
break; -mG ,_}F
} z(1`Iy M
} cs*"9nKl
c2:oM<6|
+w8$-eFY
public void splitterStop() n {..Q,z
{ tiF-lq
bStop = true; %;b]k
} wnHfjF
aA'of>'ib|
D|IS@gWa
} '8;'V%[+
mi@ni+2Tn
k;jXVa
/* `pfRY!
**FileAccess.java kQO-V4z!
*//文件访问(定位，写) ^CP>|JWD^
package NetFox; $Ao'mT
import java.io.*; *Nur>11D
TVAa/_y2`
t@q==VHF
public class FileAccessI implements Serializable{ 6bT>x5?
TEi1,yc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #q6#nfi"
RandomAccessFile oSavedFile; >O~
long nPos; lg*?w/JX+
S%jFH4#
5TLE%#G@+
public FileAccessI() throws IOException iKG,"
{ )&qr2Cm*
this("",0); e//jd&G
} )a<MW66
{TaYkuWS
F[>Y8e<[
public FileAccessI(String sName,long nPos) throws IOException nBwDq^
{ D&G^|: G
oSavedFile = new RandomAccessFile(sName,"rw"); \Yh*ywwP#
this.nPos = nPos; |g1Pr9{wy
oSavedFile.seek(nPos); I/go$@E"
} p;~oIy\,
.pIO<ZAFT
%$67*pY'JH
public synchronized int write(byte[] b,int nStart,int nLen) +NVXFjPC
{ Cm9#FA
int n = -1; 2IXtIE
try{ ywA7hm
oSavedFile.write(b,nStart,nLen); vPAL,
n = nLen; hP$5>G(3
} 5 hW#BB
catch(IOException e) \s7/`
{ /4KHf3Nr
e.printStackTrace (); |nBZ:$D
} DC0ON`
?*'0;K13
K?>sP%m)
return n; 9(lcQuE9
} RV%)~S@!R
sW76RKX8
?0+N
} svtqX-Vj"
?%$~Bb _
yYdh+x
/* d '\^S}
**SiteInfoBean.java 0 gR_1~3
*/ S}qGf%
package NetFox; rA}mp]
k+~2 vmS
*0'< DnGW
public class SiteInfoBean { 3 6t^iV*3
BDLJDyf B
g!^mewtd
private String sSiteURL; //Site's URL _} K3}}
private String sFilePath; //Saved File's Path Gh352
private String sFileName; //Saved File's Name j{6O:d6([$
private int nSplitter; //Count of Splited Downloading File 4K*st8+bl-
~RV"_8`V9
&a)d,4e<M
public SiteInfoBean() +'_ peT.8
{//nSplitter的缺省值为5 bmJdZD7-<k
//default value of nSplitter is 5 {u4AOM=)
this("","","",5); Y$s4 *)%
} N_d{E/
2Sk"S/4}Z
k106fT]eX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #Y'ewu;qJ
{ p-H}NQ\
sSiteURL= sURL; D;[%*q*
sFilePath = sPath; /4|_A {m{m
sFileName = sName; )&l5I4CIf
this.nSplitter = nSpiltter; (L:Mdo
uzhTNf
H-mQ{K^
} ]GD&EQ
ElKMd
vOv"^X
public String getSSiteURL() #/HZ[Vw
{ Q:Ma3El\
return sSiteURL; _%#Uh#7P$
} NMUF)ksjN
[3x},KM
i*@ZIw
public void setSSiteURL(String value) +.zX?}
{ J"$U$.W=
sSiteURL = value; Ctx>#uN6
} q*kLi~Oe
9FPqd8(]*V
3#y`6e=5
public String getSFilePath() 'S*]JZ1
{ }aQ*1Vcj
return sFilePath; _&S;*?K.
} 2*a9mi
QL*RzFAD3
cp0yr:~
public void setSFilePath(String value) 6cD3(//
{ 9$D}j"
sFilePath = value; [f}`reRlZ
} RxNLn/?d@
DQ9aq.;
<{@D^L6h
public String getSFileName() 5\h6'
{ yXqC
return sFileName; yPg0:o-
} ;Sg,$`]
i0*Cs#(=h
z?F`)}
public void setSFileName(String value) ?@kz`BY
{ I!SIy&=W
sFileName = value; xM@s`s|n
} ]9c{qm}y
Mpco8b-b
G~ LQM
public int getNSplitter() @"wX#ot
{ /a)^)
return nSplitter; LROrhO
} YY(_g|;?8
9c[bhGD?
53d`+an2
public void setNSplitter(int nCount) Cl3L)
{ Br.UN~q
nSplitter = nCount; V<?0(esgR
} |WSpWsr,
} RCoDdtMo
At !:d3
Db;>MWt+e
/* '-Oh$hqCx|
**Utility.java U#Iwe=
*/ K\zb+
package NetFox; esq~Ehr=
BOP7@D
RLzqpE<rJ
public class Utility { ?P4y$P
V?mk*CU
4mtO"'|
public Utility() ?$uEN_1O\@
{ rixVIfVF
{47Uu%XT
+$#XV@@~
} aof'shS8
b5I 8jPj4c
//线程睡眠 gm=C0Sp?
public static void sleep(int nSecond) wy{sS}
{ :ln?PT
try{ w4_Xby)
Thread.sleep(nSecond); i_QiE2d
} d$xvM
catch(Exception e) Bjj=UtI
{ :>Qu;Z1P
e.printStackTrace (); \I^"^'CP
} G l2WbY
} oiC@ /
Nl/ fvJ`4
//日志 R y(<6u0
public static void log(String sMsg) !VsdKG)
{ Iza;~8dH5
System.err.println(sMsg); s&Al4>}.f
} p#-=mXE/2
eibkG
a=x&sz\x
public static void log(int sMsg) dmcY]m
{ L/,gD.h^
System.err.println(sMsg); (w\|yPBB
} 13)6p|6x
} [dUAb
-o~n06p
J><hrZ
/* -N5h`Ii7
**TestMethod.java .*xO/pn
*/ 0NU3% 4?
package NetFox; qm'@o -[
9}Za_ZgG
@g]+$Yj
public class TestMethod { \2#K {
/~7M @`1
mG@[~w+
public TestMethod() RlU?F
{ ///xx/weblogic60b2_win.exe -*hPEgcV9
try{ |9Yx`_DF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DMs8B&Y=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z4` :n.
SiteFileFetch fileFetch = new SiteFileFetch(bean); u$aN~6HG
fileFetch.start(); SG&H^V8
} f)gV2f0t
catch(Exception e){e.printStackTrace ();} yx6^ mis4
VS>hi~j
#pPR>,4
} %[ *+
(~! @Uz5
7;C~>WlU
public static void main(String[] args) 3RxR'M1
{ fCnwDT
new TestMethod(); zV;NRf) 9.
} nD)SR
} Y5B!*+h
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