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)); {=9,n\85#
} zOAd~E
for(int i=0;i<nEndPos.length-1;i++) %8B}Cb&2c
{ A7Cm5>Y_S
nEndPos = nStartPos[i+1]; kYP#SH/
} Ytp(aE:
nEndPos[nEndPos.length-1] = nFileLength; #1A.?p
} !OhC/f(GBZ
} R6<X%*&%
\_VA50
`!3SF|x&
//启动子线程 p}z<Fdu0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hn7# L
for(int i=0;i<nStartPos.length;i++) ~f&E7su-6+
{ +/4A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 64 wv<r]5j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), IYE~t
nStartPos,nEndPos,i); ,B*EVN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [: n'k
fileSplitterFetch.start(); MIeU,KT#U
} a_^\=&?'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xC?6v'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HYD'.uj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B-Ll{k^
nEndPos = " + nFileLength); s0TORl6Z|
// fileSplitterFetch[nPos.length-1].start(); :%_LpZ
g{]0sn#
8rAg\H3E
//等待子线程结束 WH#1zv
//int count = 0; > ym,{EHK
//是否结束while循环 rQ{7j!Im
boolean breakWhile = false; )` SrfGp8
Hp|kQJ[LE
b"<liGh"n-
while(!bStop) #X+JHl
{ T8?Ghbn
write_nPos(); 5 Aw"B
Utility.sleep(500); ;RZ )
breakWhile = true; Di,^%
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59 T8r
for(int i=0;i<nStartPos.length;i++) y;m|
{ i<C*j4qQ
if(!fileSplitterFetch.bDownOver) UP$.+<vm
{ w8")w*9Lmg
breakWhile = false; 9d0@wq.
break; =g7x' kN
} nSDMOyj+
} zH72'"w
if(breakWhile) m+`cS=-.
break; nI?[rCM
ch*8B(:
(U DnsF
//count++; o*+"|
//if(count>4) d~])K#oJ
// siteStop(); h"B+hu
} 6%\J"AgXO
\Gef \
/*(Kr'c
System.err.println("文件下载结束！"); 5ORo3T%
} }?$F}s-
catch(Exception e){e.printStackTrace ();} E<rp7~#
} ;}I:\P
'0;l]/i.
)NW)R*m~D
//获得文件长度 c8 )DuJ#U
public long getFileSize() +)AG*
{ aL\PGdgO
int nFileLength = -1; L8@f-Kk
try{ c`)\Pb/O
URL url = new URL(siteInfoBean.getSSiteURL()); KWbI'}_z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;HfmzY(
httpConnection.setRequestProperty("User-Agent","NetFox"); '?{OZXg
EgEa1l!NSQ
dM.f]-g
int responseCode=httpConnection.getResponseCode(); (' (K9@}
if(responseCode>=400) GhAlx/K
{ N@4w! HpJ
processErrorCode(responseCode); B&M%I:i
return -2; //-2 represent access is error SBu"3ym
} 4!{KWL`A
L]|gZ&^
n1ZbRV
String sHeader; (!u~CZ;
^cC,.Fdw
{S]}.7`l9(
for(int i=1;;i++) OU\~::
{ *g"Nq+i@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1/B>XkCJ
//Utility.log(in.readLine()); /s&9SYF
sHeader=httpConnection.getHeaderFieldKey(i); tn\yI!a
if(sHeader!=null) ZoW?nxY
{ G`D`Af/B
if(sHeader.equals("Content-Length")) vQG5*pR*w
{ @Rze| T.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;J( 8 L
break; 6xmZXpd!
} 3lL-)<0A(
} F}yW/
else ](]i 'fE>
break; [-1^-bb
} KJUH(]>F
} (*9$`!wS
catch(IOException e){e.printStackTrace ();} C\3rJy(VJ
catch(Exception e){e.printStackTrace ();} Ys9[5@7
caR<Kb:;*
,$L4dF3
Utility.log(nFileLength); IxN9&xa
|)th1 UH
*\a4wZ6<3
return nFileLength; ah$b[\#C
} `6(S^P
4}baSV
%bn jgy
//保存下载信息（文件指针位置） HXC ;Np
private void write_nPos() \[i1JG
{ !RS}NS
try{ wc@X.Q[
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0cH`;!MZ
output.writeInt(nStartPos.length); ij`w} V
for(int i=0;i<nStartPos.length;i++) z]y.W`i
{ B2vh-%63
// output.writeLong(nPos); \fLMr\LL&
output.writeLong(fileSplitterFetch.nStartPos); ./Zk`-OBT
output.writeLong(fileSplitterFetch.nEndPos); 2DDtu[}
} ;u ({\K
output.close(); i v38p%Zm
} ]L.O8
catch(IOException e){e.printStackTrace ();} 9!\B6=r y4
catch(Exception e){e.printStackTrace ();} "Qc7dRmSxm
} yjX9oxhtL
3,3N^nSD
',@3>T**
//读取保存的下载信息（文件指针位置） Ykw*&opz
private void read_nPos() Wq&if_
{ CNyIQ}NJ
try{ '3fu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %JBz5G
int nCount = input.readInt(); !>&o01i
nStartPos = new long[nCount]; ]y'>=a|T
nEndPos = new long[nCount]; w+|L+h3L7
for(int i=0;i<nStartPos.length;i++) %)W2H^
{ B%b4v
nStartPos = input.readLong(); ES7>H
nEndPos = input.readLong(); %/.b~|,-
} nh>vixe
input.close(); P l]O\vh
} \'D0'\:vz
catch(IOException e){e.printStackTrace ();} K=k"a
catch(Exception e){e.printStackTrace ();} Hg izW
} v>)"HL"XG
sIGMA$EK
?P`K7
private void processErrorCode(int nErrorCode) q,|j]+9q
{ ,T$U'&;
System.err.println("Error Code : " + nErrorCode); xF'EiX~
} pJ"qu,w
ChPmX+.i_
"7F?@D$e
//停止文件下载 x2\qXN/R
public void siteStop() ?mxMk6w
{ )_S(UVI5
bStop = true; X *"i6*
for(int i=0;i<nStartPos.length;i++) YkKi|k
fileSplitterFetch.splitterStop(); oIzj,v8$
|FZ/[9*
k9 I%PH
} 37.S\gO]
} "_NN3lD)X
//负责部分文件的抓取 L48_96
**FileSplitterFetch.java &Q#66ev
*/ u^I|T.w<r6
package NetFox; {]@= ijjf
/{n-Y/jp
fxHH;hRfv
import java.io.*; yjJ5>cg
import java.net.*; |TH\`U
,<P vovg_
:{l_FY436
public class FileSplitterFetch extends Thread { vr6w^&[c^
16(QR-
H40p86@M
String sURL; //File URL `l[c_%Bm
long nStartPos; //File Snippet Start Position s*]}QmRpr
long nEndPos; //File Snippet End Position o|<!"AD7
int nThreadID; //Thread's ID N5 6g+,w%)
boolean bDownOver = false; //Downing is over 3bH'H*2
boolean bStop = false; //Stop identical N<VJ(20y
FileAccessI fileAccessI = null; //File Access interface Cnh \%OW
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-C]5>& W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U!\.]jfS
{ g:8h|w)
this.sURL = sURL; OA;XiR$xP
this.nStartPos = nStart; I,vJbvvl!
this.nEndPos = nEnd; "@0]G<H
nThreadID = id; Eo]xNn/g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ( ^Nz9{
} :*9Wh
Dp-z[]})1
8'io$6d=
public void run() k,+0u/I
{ JP[K;/
while(nStartPos < nEndPos && !bStop) ,w4V?>l
{ tl^9WG
r52gn(,
-X2Buz8
try{ (gWm,fI RZ
URL url = new URL(sURL); M-Y_ Wb3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o`z]|G1''
httpConnection.setRequestProperty("User-Agent","NetFox"); 4O!ikmY:t
String sProperty = "bytes="+nStartPos+"-"; x7<K<k;s
httpConnection.setRequestProperty("RANGE",sProperty); YO}<Ytx
Utility.log(sProperty); s R/F"
Si;H0uPO
i2SR{e8:GF
InputStream input = httpConnection.getInputStream(); 5D//*}b,
//logResponseHead(httpConnection); |#R7wnE[k~
59;KQ
2.%ITB
byte[] b = new byte[1024]; TJXT-\Vk
int nRead; LsU9 .
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p947w,1![
{ A;?|&`f
nStartPos += fileAccessI.write(b,0,nRead); {9.|2%a
//if(nThreadID == 1) hf&9uHN%7m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Em~>9f ?Q(
} _L=h0H l
l}K37f
T</F 0su|
Utility.log("Thread " + nThreadID + " is over!"); 1tFNM[R
bDownOver = true; #Ki[$bS~6
//nPos = fileAccessI.write (b,0,nRead); qF;|bF
} v0.#Sl-
catch(Exception e){e.printStackTrace ();} Q*ft7$l&
} /aZ`[m2
} n,WqyNt*
<frutU16\
oe-\ozJ0
//打印回应的头信息 draN0vf
public void logResponseHead(HttpURLConnection con) 6i3$CW
{ Z4 =GMXj
for(int i=1;;i++) &&>ekG9@
{ Wg]Qlw`\|
String header=con.getHeaderFieldKey(i); H$UcF1k<
if(header!=null) r3UUlR/Do
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 86F1.ve
Utility.log(header+" : "+con.getHeaderField(header)); sLxc(d'A
else gc$l^`+M
break; Oxd]y1
} :eVq#3}
} DEZveQr=
vUM4S26"NT
6(ol1 (U
public void splitterStop() 0flRh)[J
{ Lw>N rY(Y
bStop = true; #S"nF@
} ^k9I(f^c-_
xU`p|(SS-
)\$|X}uny&
} s?nR4
rFL;'Cj@
j&qub_j"xX
/* gRcQt:
**FileAccess.java =D"#U#>;7&
*//文件访问(定位，写) P~X2^bw
package NetFox; $(x]
import java.io.*; )lDD\J7
aQ@oH#
Otn1wBI
public class FileAccessI implements Serializable{ ^^ixa1H<
$ $mV d+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;;/{xvQ.1
RandomAccessFile oSavedFile; |P?*5xPB
long nPos; @f3E`8
AH~E)S
FfT`;j
public FileAccessI() throws IOException '!B&:X)
{ Ab.(7GFK
this("",0); [ub e6
} 67FWa
7;@]t^d=$
=41?^1\
public FileAccessI(String sName,long nPos) throws IOException g*+>H1}
{ _7_Y={4=`
oSavedFile = new RandomAccessFile(sName,"rw"); \1M4Dl5!
this.nPos = nPos; SNk=b6`9
oSavedFile.seek(nPos); J]r^W)O
} 3=V&K-
ZSo)
1G`Pmh@
public synchronized int write(byte[] b,int nStart,int nLen) fI|$K)K
{ /G`]=@~
int n = -1; `">=
try{ MiX43Pk]
oSavedFile.write(b,nStart,nLen); RT8 ?7xFc
n = nLen; w&.aQGR#
} Rf% a'b
catch(IOException e) 05^h"
{ qZZK#,Qb
e.printStackTrace (); V|R,!UND
} uHNCSzH(
62NsJ<#>
X5w$4Kj&4l
return n; ksm~<;td
} f%8C!W]Dm
{K!)Ss
)O6>*wq
} ^=*;X;7
l}P=/#</T
tT._VK]o&R
/* Rk8P ax/JK
**SiteInfoBean.java EiaW1Cs
*/ wdoR%b{M
package NetFox; dgP3@`YS
#p{4^
c[s4EUG
public class SiteInfoBean { (w zQ2Dk
?r!o~|9|
*OQ2ucC8j
private String sSiteURL; //Site's URL - ! S_ryL
private String sFilePath; //Saved File's Path f)<6
private String sFileName; //Saved File's Name %]7d`/
private int nSplitter; //Count of Splited Downloading File 2t1ZIyv3D
Kf-JcBsrT
7x8 yxE
public SiteInfoBean() (QiAisE
{//nSplitter的缺省值为5 O.JN ENZf
//default value of nSplitter is 5 UL9n-M=
this("","","",5); [.}oyz;}N
} ;O#>Y
:MDKC /mC
f<6lf7qzC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /<BI46B\
{ :2)/FPL6
sSiteURL= sURL; d0 /#nz
sFilePath = sPath; Z #m+ObHK1
sFileName = sName; .o}v#W+st
this.nSplitter = nSpiltter; NZz8j^
a09<!0Rp
y~HP>~Oh
} #Rr%:\*
`wU!`\
&Hnz8Or!
public String getSSiteURL() )WFr</z5bA
{ )=-szJjXZ
return sSiteURL; q" 5(H5
} #)VF3T@#'
'4<1 1(U
P1f[%1
public void setSSiteURL(String value) 8Cv?Z.x5
{ ^d73Ig:8q
sSiteURL = value; 2b8L\$1q
} QSf|nNT
+qdEq_m
3T0"" !Q
public String getSFilePath() f|oh.z_R
{ f`66h M[
return sFilePath; 9(<@O%YU
} Yu`~U,m
r:TH]hs12+
wwcBsJ1{
public void setSFilePath(String value) ^LzF@{ G
{ ,MIV=*
sFilePath = value; 7Fsay+a
} G .4X'
] @fk]]R
|(^PS8wG
public String getSFileName() 11;zNjD|
{ @`Su0W+.
return sFileName; oe~b}:
} f(7GX3?
~flV`wy$$1
+[g,B1jt
public void setSFileName(String value) sW8dPw O
{ "tpSg
sFileName = value; UJ6v(:z<
} eb$#A _m
lqpp)Cq
&PtJ$0%q
public int getNSplitter() "@8li^
{ IMONgFBS
return nSplitter; kB%JNMF{A
} y1L,0 ]
7"D.L-H
)@bQu~Y
public void setNSplitter(int nCount) #:%/(j
{ "U"Z 3*
nSplitter = nCount; |#N&akC
} \Y}8S/]
} mpJ#:}n
x]ot 2
&b& ,
/* ^_mj
**Utility.java y4fdq7i~}9
*/ 9=2$8JN=(l
package NetFox; !jR=pIfq
+^T@sa`[I
SByW[JE
public class Utility { @U}1EC{A
H} g{Cr"Ex
|LKXOU c
public Utility() DM>eVS3}
{ VVOd]2{
FaJ&GOM,
M\Kx'N
} m`r(p"
3=ymm^
//线程睡眠 u> 7=AlWF-
public static void sleep(int nSecond) SasJic2M
{ R{T$[$6S
try{ Xla~Yg
Thread.sleep(nSecond); 65^9
} _:27]K:
catch(Exception e) x-3\Ls[I
{ !%0 *z
e.printStackTrace (); o{[YA}xc
} IPo?:1x]s
} "snw4if
@F*%9LPv
//日志 AYx{U?0p
public static void log(String sMsg) )K
{ pyvSwD5t
System.err.println(sMsg); HyWCMK6b
} ?6Y?a2 |
D}/vLw:v
a:6m7U)P#5
public static void log(int sMsg) Tnm.A?
{ M=r)I~
System.err.println(sMsg); 5XBH$&Td
} TRq6NB
} yz8jw:d^-
v_-dx
c0u^zH<
/* 8X|-rM{
**TestMethod.java H_Q+&9^/
*/ 0"bcdG<}
package NetFox; ea')$gR
g}',(tPMZ
~Jz6O U*z
public class TestMethod { [hj6N*4y
S^\Vgi(
sLAQE64\"
public TestMethod() oILZgNe'
{ ///xx/weblogic60b2_win.exe D>tR-
try{ 9qG6Pb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Jg|XH L)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d-dEQKI?;
SiteFileFetch fileFetch = new SiteFileFetch(bean); N<injx
fileFetch.start(); e**qF=HCw
} [HZv8HU|
catch(Exception e){e.printStackTrace ();} 6,{$J
0KOgw*>_
/s}}&u/
} QMbOuw
(JFWna0@
?<'}r7D
public static void main(String[] args) a!AA]
{ SI-Ops~e
new TestMethod(); jtc]>]6i
} NHZz _a=
} s,&Z=zt0R
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