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)); ,\x$q'
} W "k|K:
for(int i=0;i<nEndPos.length-1;i++) 4kh8W~i;/
{ jqtVpNwM
nEndPos = nStartPos[i+1]; c$A@T~$
} @h9K
nEndPos[nEndPos.length-1] = nFileLength; %I0}4$
} cWM:
} 1yS&~ y?a
0MrN:M2B
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//启动子线程 |T y=7d,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \%4|t,en
for(int i=0;i<nStartPos.length;i++) EZ{\D!_Y
{ "k, K~@}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U!Mf]3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~of,,&
nStartPos,nEndPos,i); *:S~C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d"GDZ[6
fileSplitterFetch.start(); GXYj+ qJ
} +A\V)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \4QH/e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vpV$$=Qwp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?;RD u[eD
nEndPos = " + nFileLength); 61>f(?s
// fileSplitterFetch[nPos.length-1].start(); zR/IqW.`9
S(tEwXy
[xf$VkjuF
//等待子线程结束 Z'ao[CG
//int count = 0; ;W~4L+e
//是否结束while循环 {2EMz|&8
boolean breakWhile = false; HzEGq,.
Z/h|\SyJ
p&O8qAaO
while(!bStop) OfJd/D
{ GMe0;StT
write_nPos(); 7H#2WFQ7
Utility.sleep(500); kC31$jMC3!
breakWhile = true; x=vK EyS@
yKlU6t&` G
0e\y~#-
for(int i=0;i<nStartPos.length;i++) 8JP6M!F#
{ z{/LX \
if(!fileSplitterFetch.bDownOver) 2`E!|X
{ D:)~%wu Lt
breakWhile = false; <p/MyqZf
break; #<]Iz'\`
} vnZ4(
} zQ<88E&&Xs
if(breakWhile) 506V0]`/
break; 3(o7co-f
{lMqcK
E|{m"RUOy
//count++; k% NrL@z
//if(count>4) Bz:&f46{
// siteStop(); LyV#j>gD
} bM5CDzH(#X
@Kp1k> ov
!-ZP*V3}h
System.err.println("文件下载结束！"); K-6p'|
} zWtj|%ts
catch(Exception e){e.printStackTrace ();} F3 Y<ZbxT
} 7jT#BWt
|,{+;:
QY6O(=
//获得文件长度 RQ|?Ce",
public long getFileSize() NA\x<
{ *0\k Z,#BJ
int nFileLength = -1; $bFgsy*N2
try{ F^xaz^=`u
URL url = new URL(siteInfoBean.getSSiteURL()); ) G|"jFP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^Eu_NUFe
httpConnection.setRequestProperty("User-Agent","NetFox"); @ct#s:t
}H; ]k-)
F'XlJ M
int responseCode=httpConnection.getResponseCode(); f}%sO
if(responseCode>=400) /3s@6Ex}E
{ M&OsRrq
processErrorCode(responseCode); ]o `4Z"
return -2; //-2 represent access is error s<,"Hsh^CR
} TG?fUD V
g4Bg6<;
[d\#[l_
String sHeader; 3}yraX6r!
6kC)\uy
GV=V^Fl .
for(int i=1;;i++) ;2BPPZ
{ f!(cD80
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r&=r/k2
//Utility.log(in.readLine()); Etdd\^
sHeader=httpConnection.getHeaderFieldKey(i); ijg,'a~3E
if(sHeader!=null) F\:{}782u
{ L^&do98
if(sHeader.equals("Content-Length")) ^,>}%1\
{ nMeSCX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2AmR(vVa"
break; } cRi A
} 8`6 LMQ
} N0=b[%g;n
else %uF:)
break; b\H/-7<
} WI%zr2T
} 2 e)
catch(IOException e){e.printStackTrace ();} WtMcI>4w
catch(Exception e){e.printStackTrace ();} VB}PNg
g}^4^88=a
!P+~c0DF
Utility.log(nFileLength); ^j1Gmv)
6CCZda@
e$gaE</
return nFileLength; +W!'B r
} CdE2w?1
J*/$ywI
L>eQ*311
//保存下载信息（文件指针位置） P^i6MZ?
private void write_nPos() PsacXZNs\N
{ ~y( ,EO
try{ :+kg4v&r
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,!xz*o+#@
output.writeInt(nStartPos.length); Z{Lmd`<w`j
for(int i=0;i<nStartPos.length;i++) &:IfhS
{ i+kFL$N
// output.writeLong(nPos); ZK W@pW]U
output.writeLong(fileSplitterFetch.nStartPos); [J(@$Qix
output.writeLong(fileSplitterFetch.nEndPos); BHIZHp
} RI7qsm6RN
output.close(); PTfN+
} sASAsGk<
catch(IOException e){e.printStackTrace ();} /r#b
catch(Exception e){e.printStackTrace ();} Y0R\u\b
} My`josJ`Pb
'` BjRg57]
(Q*2dd>
//读取保存的下载信息（文件指针位置） ljaAB+
private void read_nPos() `Pz!SJ|
{ !xJLeQFJI]
try{ )of5229
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xF\}.OfWG
int nCount = input.readInt(); VuYWb)@
nStartPos = new long[nCount]; zM3H@;}m
nEndPos = new long[nCount]; a,F8+ Pb>
for(int i=0;i<nStartPos.length;i++) fJ|Bu("N
{ ru(?a~lF8~
nStartPos = input.readLong(); tIgCF?
nEndPos = input.readLong(); |TNiKy
} 83p$!8]u
input.close(); N7Z(lI|a;
} g(z#h$@S
catch(IOException e){e.printStackTrace ();} f6(9wz$Trt
catch(Exception e){e.printStackTrace ();} dd @COP?
} Y'+F0IZ+
8H$@Xts
P5ESrZ@f
private void processErrorCode(int nErrorCode) <*b]JY V@
{ &})4?5
System.err.println("Error Code : " + nErrorCode); PEwW*4Xo
} l72ie
_z_3%N
ZQJw2LAgO
//停止文件下载 qU /Wg
public void siteStop() |n-a\
{ [h2p8i'o
bStop = true; #7cf 8y
for(int i=0;i<nStartPos.length;i++) 8m13M5r
fileSplitterFetch.splitterStop(); !@]h@MC$7
}X W#?l
=":V WHf
} ^0BF2&Zx
} ADwwiq#E
//负责部分文件的抓取 2kmna/Qa6
**FileSplitterFetch.java f@x( ,p
*/ 8zB+%mcF
package NetFox; =>9.@`.
)4o=t.O\K
q}7Df!<|
import java.io.*; UU:QK{{E
import java.net.*; w!GU~0~3[
*M**h-p2'
2Yg[8Tm#
public class FileSplitterFetch extends Thread { MM58w3Mz
q5K/+N^2?
EF7|%N
String sURL; //File URL '=G<)z@k
long nStartPos; //File Snippet Start Position d9e H}#OY
long nEndPos; //File Snippet End Position f^yLwRUD
int nThreadID; //Thread's ID 0 S`b;f
boolean bDownOver = false; //Downing is over IB]VPj5
boolean bStop = false; //Stop identical N6 }i>";_;
FileAccessI fileAccessI = null; //File Access interface `X]2iz
iTBhLg,
gCBZA;/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "=5vgg3
{ M6>\R$
this.sURL = sURL; [2fiHE
this.nStartPos = nStart; pa> 2JF*
this.nEndPos = nEnd; DuC u6j
nThreadID = id; ~4 xBa:*z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zo638*32
} :Tl6:=B
)bN3-_
.^+$w$
public void run() 5<GRi"7A@
{ EpS8,[w
while(nStartPos < nEndPos && !bStop) _/w-gL{
{ ST[1'T+L
-"^WDs
Y Z2VP
try{ y.]]V"'2
URL url = new URL(sURL); ~X(xa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); co%_~xO
httpConnection.setRequestProperty("User-Agent","NetFox"); ,8 NEnB
String sProperty = "bytes="+nStartPos+"-"; 1R~WY'Ed
httpConnection.setRequestProperty("RANGE",sProperty); +Q#Qu0_
Utility.log(sProperty); )aA9z(x
-v+^x`HR
u#k6v\/
InputStream input = httpConnection.getInputStream(); }c#/1J7
//logResponseHead(httpConnection); %+W >+xRb
f?I *`~k
%L|bF"K5;
byte[] b = new byte[1024]; s=@CeV@4W
int nRead; HnY"6gTNK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rxk{Li<9
{ KIl.?_61O
nStartPos += fileAccessI.write(b,0,nRead); [k{iN1n
//if(nThreadID == 1) 1E_Ui1[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c89vx 9
} /g7?,/vnZ
"LaX_0t)
P&`r87J
Utility.log("Thread " + nThreadID + " is over!"); /<(ik&%N
bDownOver = true; S&) >w5*]U
//nPos = fileAccessI.write (b,0,nRead); *pUV-^uo
} x#VUEu]8
catch(Exception e){e.printStackTrace ();} nL20}"$E
} &bgi0)>
} Vxs`w
Z_WTMs:x!
Z6@J-<u
//打印回应的头信息 ?bDae%>.d,
public void logResponseHead(HttpURLConnection con) [t)i\ }V
{ ;@s~t:u
for(int i=1;;i++) oT{yttSNo
{ ''07Km@x
String header=con.getHeaderFieldKey(i); ,PxQ[CGg
if(header!=null) ^#nWgo7{7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3+uoK f[
Utility.log(header+" : "+con.getHeaderField(header)); LbknSy C
else " CoR?[,x
break; *9wHH-#
} nQ3goVRFP
} ; O0rt1
o@;_(knb
ebK wCZwK*
public void splitterStop() TBT*j&!L
{ Q kpmPQK
bStop = true; Khd,|pM
} UH|.@7w
t+q`h3
@!O{>`
} S6X<3L`FfH
T bWZw
+N_%|!F-c
/* gOAluP
**FileAccess.java VbR.tz
*//文件访问(定位，写) @1Lc`;Wd
package NetFox; ibw;BU
import java.io.*; ?\r3 _
]~ UkD*Ct
XePBA J
public class FileAccessI implements Serializable{ pjM|}i<'Q
ir#^5e@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KL`>mJo$
RandomAccessFile oSavedFile; E1_4\S*z
long nPos; tn1aH +
2jC\yY |PN
ro@BmRMW
public FileAccessI() throws IOException #9Z-Hd<
{ SiT &p
this("",0); i[#Tn52D
} $0t %}DE
Q2=~
VRt*!v<")
public FileAccessI(String sName,long nPos) throws IOException >m!.l{*j>N
{ =T]OYk
oSavedFile = new RandomAccessFile(sName,"rw"); K e8cfd~c
this.nPos = nPos; _3S{n=9
oSavedFile.seek(nPos); pnU g:R@
} .YRSd
(C%'I
,YTIYG](
public synchronized int write(byte[] b,int nStart,int nLen) k_B^2=
{ 1-#tx*>AY
int n = -1; ~T~v*'_h
try{ KK6YA
oSavedFile.write(b,nStart,nLen); !TFVBK
n = nLen; 0*^Fk=>ej
} aJ5R0Y,
catch(IOException e) L?fv5 S3
{ rGWTpN
e.printStackTrace (); 8h97~$7)
} 7Go!W(8
25L{bcng
UsTPNQj
return n; wah`
} 85mQHZ8aR
b}:Z(L,\
RAC-;~$WB
} (Wn'.|^%
*)<tyIHd
OBZj-`fqJ
/* jVz1`\Nje
**SiteInfoBean.java \<} nn?~n
*/ UL/>t}AG
package NetFox; ?6dtvz;K+?
,n*.Yq
|};~YMH
public class SiteInfoBean { !NCT) #G`
WxFjpJt
B.?yHaMI[
private String sSiteURL; //Site's URL /Q!F/HY3ZS
private String sFilePath; //Saved File's Path vF,l?cU~
private String sFileName; //Saved File's Name ($wYawz
private int nSplitter; //Count of Splited Downloading File C N"c
zkMQ=,[
dY,'6JzC
public SiteInfoBean() 2Y+*vNs3
{//nSplitter的缺省值为5 fHigLL0B
//default value of nSplitter is 5 61'7b`:(hi
this("","","",5); Aq"_hjp
} AOe~VW
4v>V7T.
MPt7 /
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F!xK#~e
{ S;])Nt'X'
sSiteURL= sURL; URAipLvN
sFilePath = sPath; EVf'1^f
sFileName = sName; J.<m@\U
this.nSplitter = nSpiltter; lwU&jo*@
`&_qK~&/X
Z8T{Xw6%
} =9c24j
-4Xr5j%o
Pc3u`QL?
public String getSSiteURL() <n><A+D
{ BWs\'B
return sSiteURL; 6"DvdJ0MB
} r#XDgZtI
p})&Zl)V
R:e:B7O~0
public void setSSiteURL(String value) R9W(MLe58
{ G2Apm`/ y
sSiteURL = value; +|.#<]GA
} O/k4W#
8[DD=[&
t~AesHZpk
public String getSFilePath() j<!$ug9VA
{ gFKQm(0g2
return sFilePath; GB+G1w
} +LUL-d
Xm*Dh#H
ecHy. 7H
public void setSFilePath(String value) <W?,n%
{ r[gV`khka
sFilePath = value; S2*:]pYf}
} !B\\:k]aO^
[)*fN|Hy
dI>oHMC
public String getSFileName() b#P8Je`;9
{ ENGw <
return sFileName; 3{%/1>+x5
} 8\yH7H
u%|VmM>
Kg.E~
public void setSFileName(String value) :g,rl\S7
{ =v_ju;C=
sFileName = value; %|;^[^7+}t
} _ pJU~8
8^^al!0K~
mU3UQ j
public int getNSplitter() tuv4~i<
{ B^6P6,
return nSplitter; rOcfPLJi0
} (s9?#t6
9oaq%Sf
N%T-Q9k
public void setNSplitter(int nCount) k<:!^_3H
{ ic3qb<2
nSplitter = nCount; eQ*gnV}rE%
} lFB Ka ,6
} ~[[a7$_4
@ O%m,
P[Qr[74)
/* !Zs;m`j&9
**Utility.java L\b$1U!i
*/ bT8BJY%+
package NetFox; J+9D/VT
QZDGk4GG
sT/pA^rnnR
public class Utility { v+\E%H
mX<D]Z< k
fBQZ=zh
public Utility() ok7DI
{ B[k"xs
Uqkh@-6-
%D&FnTa
} `E}2|9
//WgK{Mt
//线程睡眠 MM^tk{2?.
public static void sleep(int nSecond) (US8Sc
{ M14pg0Q
try{ zis-}K<
Thread.sleep(nSecond); Vv zd>yII
} SK-|O9Ki
catch(Exception e) z`TI<B
{ H-I*;
e.printStackTrace (); >f_D|;EV
} 9%)'QDVGLf
} }3+q}_3
RRV&!<l@$
//日志 Ir]b.6B
public static void log(String sMsg) FCI38?`%
{ JhuKW>7
System.err.println(sMsg); _Jx?m
} >q]r)~8F^
*gBaF/C
L*FnFRhU
public static void log(int sMsg) }p "HD R>
{ _msDf2e9
System.err.println(sMsg); Va9vDb6
} {Q4=GrS
} dAga(<K
vnIxI a
71f]KalqL
/* X5)>yM^N`
**TestMethod.java n+xM))
*/ RPLr7Lb
package NetFox; !lHsJ)t
TzPVO>s
dedi6Brl
public class TestMethod { m 81\cg
}De)_E\~
\2~.r/`1
public TestMethod() fV[xv4D.
{ ///xx/weblogic60b2_win.exe /ZD/!YD&R
try{ 1f~_# EIC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QI!:+8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L9G=+T9
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;M}bQ88
fileFetch.start(); .p0;y3so4
} J,jl(=G
catch(Exception e){e.printStackTrace ();} 23Eg|Xk
heRQ|n.Dz)
8lbNw_U
} $|AvT;4
ncihc$V<
}_u)3X.O
public static void main(String[] args) 'zRd?Z>%
{ a)}?rzT]
new TestMethod(); g%^Zq"
} 6"gncB.
} b}[{'
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