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)); {55f{5y3 c
} H<tU[U=G
for(int i=0;i<nEndPos.length-1;i++) "xNP"S
{ i91k0q*di
nEndPos = nStartPos[i+1]; TR%8O;
} 7m%[$X`
nEndPos[nEndPos.length-1] = nFileLength; BMtk/r/
} shEAr*u
} N8DouDq
\Xe{vlo>h
r$<M*z5q(\
//启动子线程 G#~U\QlG-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yg4#,4---b
for(int i=0;i<nStartPos.length;i++) ;oO_5[,M
{ C~WWuju'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A-, hm=?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =b8u8*ua
nStartPos,nEndPos,i); |h\A5_0_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c D.;
fileSplitterFetch.start(); X3][C
} 9e4`N"#,lI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QQ=Kj%R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <\$?.tTZ{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j'OXT<n*
nEndPos = " + nFileLength); At'M? Q@v
// fileSplitterFetch[nPos.length-1].start(); $3gM P+
"<Yxt"Z4
<g&.UW4
//等待子线程结束 ,g4T>7`&U%
//int count = 0; mi1^hl'2
//是否结束while循环 $KhD>4^jL
boolean breakWhile = false; RY3=UeoF
+~|Jn_:A f
G.$KP
while(!bStop) fQ1Dp
{ I Bko"|e@
write_nPos(); mmG]|Cl@
Utility.sleep(500); F8#MI G
breakWhile = true; Vvp{y
I2-ue 63 ?
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for(int i=0;i<nStartPos.length;i++) hgbf"J6V8
{ VrWQ]L
if(!fileSplitterFetch.bDownOver) QpA$='
{ #R7hk5/8n}
breakWhile = false; 1Y%lt5,*
break; -0TI7 @
} HXX9D&c4R
} a^\F9^j
if(breakWhile) g}IOHE
break; zl|+YjR
r;{ggwY&J
$Ld-lQsL
//count++; 2 6 >9$S
//if(count>4) &gr T@
// siteStop(); p8"C`bCf
} cm!|A?-<
.l|29{J
stMxlG"d
System.err.println("文件下载结束！"); tc{l?7P
} Ov4=!o=
catch(Exception e){e.printStackTrace ();} @$Yk#N;&(
} 45x4JG
ROvY,-?
~*J <lln
//获得文件长度 Dm$SW<!l|
public long getFileSize() #DARZhU)
{ um%s9
int nFileLength = -1; '+ mI
try{ wp'[AR}
URL url = new URL(siteInfoBean.getSSiteURL()); lHPnAaue@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yE.st9m
httpConnection.setRequestProperty("User-Agent","NetFox"); -[&Z{1A4x4
=T#hd7O`V
8k)*f+1o
int responseCode=httpConnection.getResponseCode(); ,1cpV|mAr
if(responseCode>=400) s];0-65)
{ _00}O+GLM4
processErrorCode(responseCode); -m[ tYp,q
return -2; //-2 represent access is error xA<-'8ST
} kM@e_YtpY
bxO[y<|XL
:'xZF2
String sHeader; {<a)+S.6U
sva-Sd8
[z"oi'"fQ
for(int i=1;;i++) )2q r^)
{ !I\eIV>0b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~C3J-z<
//Utility.log(in.readLine()); tOte[~,
sHeader=httpConnection.getHeaderFieldKey(i); |eg8F$WU
if(sHeader!=null) xi4b;U j
{ W$Xr:RU
if(sHeader.equals("Content-Length")) PW iuM=E
{ .:4*HB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z\]LG4N?
break; v~W;&{
} qx9;"Ut
} c<~DYe;;
else mkPqxzxbrL
break; tk:nth
} j^v<rCzc(
} ]Nw]po+
catch(IOException e){e.printStackTrace ();} m5a'Vs
catch(Exception e){e.printStackTrace ();} B*E"yB\NV
I[gPW7&S@
WvoIh4]
Utility.log(nFileLength); 9$qw&j[
-e?n4YO*\
VKw.g@BY
return nFileLength; XR p60i6f
} lqgR4 !
2^75|Q
{?++T 0
//保存下载信息（文件指针位置） KY0<N9{
private void write_nPos() &U CtyCz
{ n5efHJU
try{ L?P[{Ohh/
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^|vP").aQm
output.writeInt(nStartPos.length); Fp"c {
for(int i=0;i<nStartPos.length;i++) 9b&;4Yq!f
{ b$pCp`/MT
// output.writeLong(nPos); /J Y6S
output.writeLong(fileSplitterFetch.nStartPos); 1}SON4U
output.writeLong(fileSplitterFetch.nEndPos); k_Sm ep
} 7q 5 \]J[
output.close(); ?)-anoFyVW
} ?' mP`9I
catch(IOException e){e.printStackTrace ();} 0LP0q9S:9
catch(Exception e){e.printStackTrace ();} EP<{3fy
} ?B)e8i<[f
)7-mALyW
WP Gp(Xw
//读取保存的下载信息（文件指针位置） ,`'A"]"
private void read_nPos() (lq%4h
{ j~=<O<P
try{ sFvYCRw /
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n=0^8QQ
int nCount = input.readInt(); u-bgk(u
nStartPos = new long[nCount]; +afkpvj8
nEndPos = new long[nCount]; Sj*W|n\gj
for(int i=0;i<nStartPos.length;i++) M0e&GR8<z>
{ kmlO}0
nStartPos = input.readLong(); u[4h|*'"|
nEndPos = input.readLong(); [H9<JdUZ
} V$iA3)7W%
input.close(); /,j'Vr\"
} 8/y8tMm]
catch(IOException e){e.printStackTrace ();} J-azBi
catch(Exception e){e.printStackTrace ();} mi5bk>o
} /xr75|-8
`#r/L@QI
x>Dix1b:.
private void processErrorCode(int nErrorCode) 5p-vSWr!
{ +# !?+'A
System.err.println("Error Code : " + nErrorCode); BLt_(S?Z`
} (JE&1 @
/}%C'
o/vD]Fs
//停止文件下载 zWhzU|=8
public void siteStop() aW;)-0+
{ t-iQaobF
bStop = true; _`laP5~
for(int i=0;i<nStartPos.length;i++) hv#LKyp%
fileSplitterFetch.splitterStop(); ^)$T`
7s{['t
}s#4m
} _W,?_"[R=
} rJtk4hOF
//负责部分文件的抓取 P.=Dd"La
**FileSplitterFetch.java 4{ZVw/VP,-
*/ yFDt%&*n^
package NetFox; naeppBo
zP@\rZ@4
onS4ZE3B
import java.io.*; *13-)yfd
import java.net.*; M0)ZJti
Fa </
OU^I/TU
public class FileSplitterFetch extends Thread { &sXk!!85:
D$D;'Kij
Pp4Q)2X
String sURL; //File URL Lm0q/d2|\X
long nStartPos; //File Snippet Start Position `d x.<R#,
long nEndPos; //File Snippet End Position qjf4G[]!
int nThreadID; //Thread's ID O -p^S
boolean bDownOver = false; //Downing is over <K/iX%b?
boolean bStop = false; //Stop identical >Il{{{\>
FileAccessI fileAccessI = null; //File Access interface :g-vy9vb
Y8fel2;
!NKPy+v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w2`JFxQ^x
{ 62[_u]<Yub
this.sURL = sURL; 6pZ/C<Y|W
this.nStartPos = nStart; 6$csFW3R
this.nEndPos = nEnd; X&@>M}
nThreadID = id; wLg@BSC.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y]B9*^d<
} q'Y)Y(d
u=#_8e(9Z
Cs,t:ajP
public void run() ,ob)6P^rw
{ Q%V530 P;
while(nStartPos < nEndPos && !bStop) m8gU8a"(
{ O"RIY3m
/$FpceB!W
"Gq%^^*
try{ :&RpB^]
URL url = new URL(sURL); I Vw'YtZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wc}4:~
httpConnection.setRequestProperty("User-Agent","NetFox"); <c [X^8
String sProperty = "bytes="+nStartPos+"-"; KJV],6d
httpConnection.setRequestProperty("RANGE",sProperty); FuFICF7+C
Utility.log(sProperty); Rp}Sm,w(
Q[aBxy (
H^$7=
InputStream input = httpConnection.getInputStream(); COH>B1W@
//logResponseHead(httpConnection); &>ykkrY
_w%{yF6
A{DE7gp!
byte[] b = new byte[1024]; Z[\nyj
int nRead; ),-MrL8c%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _M- PF$
{ /AUX7 m.8
nStartPos += fileAccessI.write(b,0,nRead); ? 8S~R
//if(nThreadID == 1) TLz>|gr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); id1gK(F8H
} 'puiahA
.bRDz:?j
bHzH0v]:
Utility.log("Thread " + nThreadID + " is over!"); cNl$ vP83z
bDownOver = true; -e*(+
//nPos = fileAccessI.write (b,0,nRead); - KaU@t
} cA!o xti
catch(Exception e){e.printStackTrace ();} '^,|8A2
} uC 2{ Mmy
} 0qN+W&H
rp!{QG
|W|RX3D
//打印回应的头信息 D}nRH@<`
public void logResponseHead(HttpURLConnection con) "Y=4Y;5q
{ 3rx8"
for(int i=1;;i++) d{]2Q9g
{ ?T'a{~]R
String header=con.getHeaderFieldKey(i); ey U*20
if(header!=null) /@LUD=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mnq1WU;<
Utility.log(header+" : "+con.getHeaderField(header)); __-V_(/b,x
else ^'hh?mL
break; }>'1Qg
} E*}1_,q)
} K|rG&#1J
7x(z
-Vjrh/@
public void splitterStop() Tpp?(lT7r
{ XhJYsq]]J
bStop = true; .:SY:v r
} ?]58{O(?c
9XN/ wp
:b(Nrj&TQ[
} "J%dI9tM{
0NyM|
?T8^tGD[
/* ]_:j+6i
**FileAccess.java 5R*55@)
*//文件访问(定位，写) #pWeMt'
package NetFox; VP"C|j^I
import java.io.*; ;:w0%>X^
p+xjYU4^C
0G#s/u#
public class FileAccessI implements Serializable{ Y?IXV*J
dpB\=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x I(X+d``
RandomAccessFile oSavedFile; Y;>D"C..
long nPos; ~s) `y2Y
<USr$
z_t%n<OvK
public FileAccessI() throws IOException <io;d$=}
{ GFYHt!&[\
this("",0); UiN6-{v<2
} 91}kBj
h@D!/PS
PKX Tj6hj)
public FileAccessI(String sName,long nPos) throws IOException l1"*
{ y-@{
oSavedFile = new RandomAccessFile(sName,"rw"); m+pFU?<|
this.nPos = nPos; s)7sgP
oSavedFile.seek(nPos); 3;wOA4ur
} <4D.H
.2QZe8"
)t$o0!
public synchronized int write(byte[] b,int nStart,int nLen) k'-5&Q
{ ^:^8M4:
int n = -1; :<R"Kk@
try{ ]+@I]\S4
oSavedFile.write(b,nStart,nLen); $/$ 5{<
n = nLen; Ab:+AC5{
} UO_tJN#X
catch(IOException e) 5>S)+p
{ I_iXu;UX
e.printStackTrace (); xC-&<s
} _{y4N0
e<HHgC#J
}/.GB5Ej
return n; [>LL
} sx@%3j
'2xfU
*.A{p ;JC(
} 3mLtnRX[m
]}>uvl^l
W$Op/
/* *dX 7
**SiteInfoBean.java t4r%EP|Zt
*/ +YCKd3/
package NetFox; yFjjpEpnFt
"D7wtpJ
50NLguE
public class SiteInfoBean { #A9rI;"XI
oO&R3zA1d
*QP+p,L*
private String sSiteURL; //Site's URL jLF,R7t
private String sFilePath; //Saved File's Path iJ!p9E*(
private String sFileName; //Saved File's Name k/2TvEV3=
private int nSplitter; //Count of Splited Downloading File -=a,FDeR
nn{PhyK
Xx e07J~
public SiteInfoBean() 3 cF4xUIZ
{//nSplitter的缺省值为5 !A&>Eeai
//default value of nSplitter is 5 @ACq:+/Qc
this("","","",5); raB',Vp
} +`l)W`zX
2HF_kYZ
Y3?)*kz%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) XSe\@t~&g
{ &W$s-qf".
sSiteURL= sURL; &a?k1R>
sFilePath = sPath; @$!rgLyL[
sFileName = sName; sJ5Ws%q
this.nSplitter = nSpiltter; J6RzN'j
,^uQw/
Q> J9M`a
} }C<$q
W?R@ eq.9
:L5k#E"u
public String getSSiteURL() i{4J$KT
{ 2su/I
return sSiteURL; 4-JyK%m,0
} W9/HM!
!]t5(g_
`xF^9;5mi
public void setSSiteURL(String value) Qk]^]I
{ agp7zw=N
sSiteURL = value; EdC/]
} tM3Q;8gB!
a?8boN(
5 =Op%
public String getSFilePath() 5LJ0V
{ H_d^Xk QZ
return sFilePath; Rh#QPYPq
} M992XXd
)h`8</#m{
MWJ}
public void setSFilePath(String value) s&F& *5W
{ ';KWHk8C
sFilePath = value; 84A:Rd'k3)
} _DLELcH Y
0rCQz3gh1
uG=~kO
public String getSFileName() ~+CEek
{ fRomP-S
return sFileName; r&ux|o+
} lkJ"f{4f
QyD(@MFxb
<N,:w`g#
public void setSFileName(String value) L-[A1#n
{ uo-1.[9ds
sFileName = value; eNu]K,rT
} L*(`ccU
G|.6%-
#&K?N
public int getNSplitter() Ox9M![fC
{ UOn:@Qn
return nSplitter; 8'#L+$O &N
} ErxvGB(2
EHk$,bM
_@OS,A
public void setNSplitter(int nCount) KtD XB>
{ 9NeHN@D)
nSplitter = nCount; Y@ X>ejk"
} )LTX.Kg
} V)A7q9Bum
xv~Sk2Z+d
P71] Z
/* W:JR\KKU
**Utility.java o'K= X E
*/ !nL>Ly
package NetFox; KpC!C9
@|D#lBm
[,sm]/Xlc
public class Utility { ^X ~S}MX
ti!kJ"q
2B b,ZC*
public Utility() Hq#q4Y
{ ]DjnzClx
Scfe6+\EW
$ D.*r*c6
} u4|)A4n
jM:|%o
//线程睡眠 L [&|<<c
public static void sleep(int nSecond) 1|:'jK#gE
{ /<1zzeHRSD
try{ +h@ZnFp3
Thread.sleep(nSecond); oc;4;A-;`c
} SvQ!n4 $
catch(Exception e) *yYeqm
{ 8(g}/%1mt3
e.printStackTrace (); p# JPLCs
} ';xp+,'}\
} #=N6[:,
@6b4YV h
//日志 uc aa;zj
public static void log(String sMsg) eh}|Wd7J
{ B*:W`}G]_c
System.err.println(sMsg); ?-JW2 E"uT
} Q7-'5s
iLQ;`/j
2=7:6Fw
public static void log(int sMsg) )=AWgA
{ jHk.]4&0
System.err.println(sMsg); sKC(xO@L;`
} ,*8)aZ1k
} gO#%* W
XZT|ID_u"
O Ke 9/._
/* JqV}$E"M2
**TestMethod.java <[vsGUbc
*/ ce:wF#Qs
package NetFox; >Se-5QtLcf
Kx02 2rgDU
/0b7"Kr
public class TestMethod { N ;Cs? C
M[cAfu
qtuT%?wT@Z
public TestMethod() kRV]`'u,
{ ///xx/weblogic60b2_win.exe dF7`V J2
try{ W&HxMi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @H}{?-XyA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T?CQgVR
SiteFileFetch fileFetch = new SiteFileFetch(bean); =^z*p9ZB
fileFetch.start(); [9yd29pQ]
} ]e$n;tuW
catch(Exception e){e.printStackTrace ();} 9<.8mW^68
?}HZJ@:lB
= u&dU'@q
} f9t+x+ Z
I#;.;%u
3gYtu-1
public static void main(String[] args) <?h(Dchq
{ ~:*V'/2k
new TestMethod(); #vc!SI
} MzF,is
} F~/~_9RJ
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