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)); ;*ni%|K
} U3{4GmrT
for(int i=0;i<nEndPos.length-1;i++) 9}L2$^#,NA
{ J1Az+m
nEndPos = nStartPos[i+1]; b|;h$otC
} (_6JQn
nEndPos[nEndPos.length-1] = nFileLength; O1wo KkfV
} iXWB
} j,lI\vw<
l|iOdKr h
Pc7p2
//启动子线程 =''b`T$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O%6D2d
for(int i=0;i<nStartPos.length;i++) cV_-Bcb
{ Oi]B%Uxy=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u^#e7u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =BJe}AV
nStartPos,nEndPos,i); 2$`Y 4b3t
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .:GOKyr(~
fileSplitterFetch.start(); %<'.c9u5
} q*C-DiV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YpRhl(|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SXN]${
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pf+VYZ#)
nEndPos = " + nFileLength); |[>yJXxEL@
// fileSplitterFetch[nPos.length-1].start(); 7$t['2j3
#!%zf{(C+
"Nz@jv?
//等待子线程结束 }' sW[?ik
//int count = 0; ZU;jz[}
//是否结束while循环 O: #SjjK
boolean breakWhile = false; Qw }1mRv
ckv8QAm
@`8a3sL)
while(!bStop) x8~*+ j
{ Li$2 Gpc/
write_nPos(); j)Kd'Va
Utility.sleep(500); fO .=i1 E}
breakWhile = true; m~fDDQs
]*Q,~uV^|
w`3.wALb
for(int i=0;i<nStartPos.length;i++) 4HX;9HPHE<
{ x5Fo?E
if(!fileSplitterFetch.bDownOver) 9?~6{!m_9
{ A wk1d
breakWhile = false; 98 ]pkqp4
break; ?r5a*
} <h}x7y?
} ='_3qn.
if(breakWhile) +c, ^KHW
break; KrHKM3<
o^//|]H3Y
c': 4e)
//count++; H*P+>j&
//if(count>4) hY!>>
// siteStop(); t~nW&]E
} V0&7MY*
Kv<mDA!
C>mFylN
System.err.println("文件下载结束！"); fX6pW%Q'6
} qPWf=s7!
catch(Exception e){e.printStackTrace ();} apgKC;
} H\N}0^ea
o@]n<ZYo
wL^x9O|`p9
//获得文件长度 3>73s}3
public long getFileSize() qt/6o|V
{ Y9vVi]4
int nFileLength = -1; VGu(HB8n#
try{ yOvV"x]
URL url = new URL(siteInfoBean.getSSiteURL()); UvB\kIH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v0tFU!Q%
httpConnection.setRequestProperty("User-Agent","NetFox"); 4^4T#f2=e
TcJJ"[0
|TkicgeS
int responseCode=httpConnection.getResponseCode(); mqUDve(
if(responseCode>=400) 8m `Y
{ @~N"MsF3
processErrorCode(responseCode); "wKJ8
return -2; //-2 represent access is error 8x7TK2r
} #N64ZXz_
hNgT/y8
SMRCG"3qwA
String sHeader; X}C8!LA
U2vb&Qu/
a|3+AWL%
for(int i=1;;i++) 4e; le&
{ px+]/P<dX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )hoVB
//Utility.log(in.readLine()); _FS #~z'j
sHeader=httpConnection.getHeaderFieldKey(i); yfR0vp<&
if(sHeader!=null) *ezft&{)`
{ uGW#z_{(n
if(sHeader.equals("Content-Length")) >c5
{ xXmlHo<D
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7M5HvG#w%
break; ;pfN
} Ukf:m&G
} -~4kh]7%
else ?A r}QN
break; 42-T&7k
} BePb8 k<y
} d/$e#8
catch(IOException e){e.printStackTrace ();} h4Arg~Or
catch(Exception e){e.printStackTrace ();} Ah5o>ZtcO
"SWL@}8vx
REi"Aj=
Utility.log(nFileLength); 3!QXzT$E
$M4_"!
!O'p{dj][
return nFileLength; ,+gtr.
} xt`a":lru
)qFqf<:yc
w Bm4~~_
//保存下载信息（文件指针位置） HTMo.hr
private void write_nPos() "@5{=
{ kXUJlLod
try{ mYXL
output = new DataOutputStream(new FileOutputStream(tmpFile)); (r}StR+
output.writeInt(nStartPos.length); n%~r^C_
for(int i=0;i<nStartPos.length;i++) cP@H8|c=
{ ]2iIk=r$
// output.writeLong(nPos); .i` -t"
output.writeLong(fileSplitterFetch.nStartPos); _25PyG
output.writeLong(fileSplitterFetch.nEndPos); F4Cq85#
} t 0p
output.close(); O]F(vHK\
} HyYJ"54
catch(IOException e){e.printStackTrace ();} IM2<:N%'
catch(Exception e){e.printStackTrace ();} G'nSnw
} 1UB.2}/:
UalwK
A4;~+L:M
//读取保存的下载信息（文件指针位置） .uN(44^+x
private void read_nPos() EF=5[$ u
{ G[OJ<px
try{ ^d(gC%+!u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2t{Tz}g*
int nCount = input.readInt(); _ph1( !H$
nStartPos = new long[nCount]; iP$>/[I
nEndPos = new long[nCount]; -ntQqHs
for(int i=0;i<nStartPos.length;i++) 0YoV`D,U
{ nI+.De~
nStartPos = input.readLong(); ^ ~Tn[w W_
nEndPos = input.readLong(); EgzdRB\Cf
} j4=\MK
input.close(); "#f5jH
} rO/Sj<0^
catch(IOException e){e.printStackTrace ();} a^O>i#i
catch(Exception e){e.printStackTrace ();} X]GodqL\
} #}tdA( -
qpa}6JVQ+j
"Z dI~
private void processErrorCode(int nErrorCode) wg:\$_Og
{ ps/|^8aGZ
System.err.println("Error Code : " + nErrorCode); "`Xbi/i
} yaHkWkl =
eOZ~p
-`t9@1P> =
//停止文件下载 .I^Y[_.G
public void siteStop() `P*wZKlW
{ $8[JL\
bStop = true; Dx9k%G)!
for(int i=0;i<nStartPos.length;i++) vP%:\u:{
fileSplitterFetch.splitterStop(); 5.kKg=a
2Z`Jr/
{?3i^Q=V
} 6eNBldP!
} @TzUcE
//负责部分文件的抓取 }C~9?Y
**FileSplitterFetch.java #Ny+6XM
*/ Yb:F,d-Ya
package NetFox; ?dCJv_w
0AhUH|]
,E+\SBQS_
import java.io.*; scrss
import java.net.*; wDBU+Z
lr -+|>M)
]^@m $O
public class FileSplitterFetch extends Thread { ^j1G08W
O8LIKD_I[
DKl\N~{F
String sURL; //File URL gN<J0c)
long nStartPos; //File Snippet Start Position FJW,G20L
long nEndPos; //File Snippet End Position ~C?)- ]bF
int nThreadID; //Thread's ID xBqZ: BQ
boolean bDownOver = false; //Downing is over y+Bxe)6^V
boolean bStop = false; //Stop identical )31xl6@
FileAccessI fileAccessI = null; //File Access interface =:H EF;!
#X?E#^6?E
$]^Io)}f@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A 0;ng2&
{ H*",'`|-
this.sURL = sURL; 1XHE:0!dQ
this.nStartPos = nStart; OgCNqW d-
this.nEndPos = nEnd; >V>GiSni
nThreadID = id; 81)i>]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DMKtTt[}
} x5M+\?I<2
sAF="uB
^<j =.E
public void run() D\pX@Sx,v[
{ D28>e
while(nStartPos < nEndPos && !bStop) Pup%lO`.0
{ OM@z5UP
>.hDt9@4
C!Fi&~
try{ !d95gq<=>
URL url = new URL(sURL); 0J;Qpi!u2v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !'Hd:oD<
httpConnection.setRequestProperty("User-Agent","NetFox"); a!;#u8f
String sProperty = "bytes="+nStartPos+"-"; V2'5doo
httpConnection.setRequestProperty("RANGE",sProperty); &=wvlI52`
Utility.log(sProperty); qGP}
vxrqUjK7
&@D\4b,?nm
InputStream input = httpConnection.getInputStream(); 7~L_>7;
//logResponseHead(httpConnection); ( F4c0
$A T kCO
H,LJ$ py
byte[] b = new byte[1024]; <%=<9~e
int nRead; }gd'pgN"t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]q&NO(:kbq
{ CKC5S^Mx
nStartPos += fileAccessI.write(b,0,nRead); S{,|Fa^PPO
//if(nThreadID == 1) ao@CPB6N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &{ZUY3
} lA4TWU (]
EWOa2^%}Z\
U+!&~C^y
Utility.log("Thread " + nThreadID + " is over!"); *dsI>4%m
bDownOver = true; F]s:`4
//nPos = fileAccessI.write (b,0,nRead); (?"z!dgc
} y8} /e@&
catch(Exception e){e.printStackTrace ();} =RQI5nHdw
} mo&9=TaG
} d *#.(C9^
|n~,{=
]oC"gWDYu
//打印回应的头信息 CW]Th-xc
public void logResponseHead(HttpURLConnection con) 2)-4?uz~
{ Y)l=r^Ap>
for(int i=1;;i++) `O0y8
{ DZ9^>`*
String header=con.getHeaderFieldKey(i); Ep3I*bQ Y
if(header!=null) > iYdr/^a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uJ0Wb$%
Utility.log(header+" : "+con.getHeaderField(header)); F&
else R]0`-_T
break; Ei=rBi
} $KlaZ>Dh
} ]0W64cuT
3jHg9M23[^
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public void splitterStop() =r3g:j/>q
{ 8]rObT9>
bStop = true; :39arq
} 2IGU{&s
m7i(0jd +
Jm"W+! E
} U]g9t<jD
|I{3~+E h
0|8cSE< i
/* ew]G@66
**FileAccess.java 9~jS_Y)"
*//文件访问(定位，写) KL$>j/qT
package NetFox; *kcc]*6@s
import java.io.*; O- LwX >
a2/Mf
cvhwd\
public class FileAccessI implements Serializable{ 6\`8b&'n
;' H\s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O\)Kg2
RandomAccessFile oSavedFile; ]q4(%Q
long nPos; IreY8.FND
ai;Q,Vy
]Tg@wMgI
public FileAccessI() throws IOException # s7e/GdKb
{ Ge7B%p8
this("",0); {-f%g-@L6|
} I5`>XfO)
]>%2,+5
L4bYVTm|
public FileAccessI(String sName,long nPos) throws IOException C ,|9VH
{ B<n[yiJ}
oSavedFile = new RandomAccessFile(sName,"rw"); g,W34*7=Q
this.nPos = nPos; _6'@#DN
oSavedFile.seek(nPos); PN:`SWP
} OhlK;hvdB*
62y:i
xtKU;+#
public synchronized int write(byte[] b,int nStart,int nLen) %r*,m3d
{ \u))1zRd
int n = -1; pZ3sp!
try{ o=K9\l
oSavedFile.write(b,nStart,nLen); 96J]g*o(uU
n = nLen; )=MK&72r
} rK`^A
catch(IOException e) iHK.hs;
{ *c&OAL]
e.printStackTrace (); S8v?H|rm
} lNtxM"G&
&K(y%ieIJ
K<`W>2"
return n; c h((u(G
} @+Sr~:K
#g0N/
xXa4t4gR
} cMnN} '
FQ`1c[M@
9!Jt}n?!g
/* <r`;$K
**SiteInfoBean.java %<[{zd1C-
*/ =&qH%S6
package NetFox; cAot+N+9|]
f?ibyoXL
^;.u}W
public class SiteInfoBean { z@pa;_
[@8po-()L
P8|ANe1 v
private String sSiteURL; //Site's URL D6+3f#k6
private String sFilePath; //Saved File's Path HW,v"
private String sFileName; //Saved File's Name }#%YeCA?
private int nSplitter; //Count of Splited Downloading File )pT5"{
ccPWfy_
jYFmL_{
public SiteInfoBean() /h.{g0Xc
{//nSplitter的缺省值为5 =Y6W Qf
//default value of nSplitter is 5 hsS&|7Pt
this("","","",5); OVU)t]
} EzjK{v">
)T^wc:
g,M-[o=Fk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DI2e%`$
{ )oz2V9X{
sSiteURL= sURL; W*CRxGyZCl
sFilePath = sPath; d|7LCW+HW
sFileName = sName; gO"G/
this.nSplitter = nSpiltter; u a_w5o7
>A6W^J|[
Ol+D"k~<C
} &z:bZH]DH
Ba|}$jo
W} H~ka
public String getSSiteURL() ~u2f`67{
{ 3W_7xLA
return sSiteURL; W|2|v?v
} II.:k.D`
qm:C1#<p
*?HoN;^
public void setSSiteURL(String value) `67i1w`
{ Wkjp:`(-$r
sSiteURL = value; |Rkw/5
} ZAN~TG<n
r~f;g9I
Dv/7w[F
public String getSFilePath() 0;">ETh=
{ nQ+5jGP1
return sFilePath; B>!mD{N
} 5 m-/N?c
6Q]c}
a~_JTH4=t
public void setSFilePath(String value) M."/"hV`-
{ 4W*o:Y!
sFilePath = value; 7_l Wr
} 5=|h~/.k
M80Q6K
UWV%y P
public String getSFileName() uK"FopUJ4i
{ tJ>>cFx
return sFileName; `VO;\s$5j
} W$NFk(
YARL/V
(Q% @]
public void setSFileName(String value) Jk&!(YK&
{ *#Ia8^z=p
sFileName = value; m+s*Io{Ip
} 2 A!*8w
wyB]!4yy,
<Y?Z&rNb
public int getNSplitter() FP=- jf/
{ _!DH/?aU
return nSplitter; i)X~L4gn
} g%S/)R,,ct
tR'RB@kJ
-WqhOZ
public void setNSplitter(int nCount) a_5s'Dh
{ ;iKtv+"
nSplitter = nCount; L@AFt)U
} Nr>UZlU8
} L f"!:]
CV"}(1T
a"U3h[;$y
/* SIrNZ^I
**Utility.java C@`#@1X
*/ ,IboPh&Q78
package NetFox; w$f_z*/
1[Yl8W%pj
#n|5ng|CJ
public class Utility { p+]S)K GZw
&>+T*-'
`IwZVz
public Utility() b=MW;]F
{ N^[ F+y
h092S|iY
$#D#ezvxe
} '{ =F/q
CS~onf<xz
//线程睡眠 IL.bwtpQD
public static void sleep(int nSecond) -Z,r\9d
{ g{}<ptx]
try{ y<- ]'Yts
Thread.sleep(nSecond); ` wEX;
} 7MrHu2rZ=
catch(Exception e) LZ_VLW9wE
{ "M iJM+,
e.printStackTrace (); =h-EN_[
} M]{~T7n-
} T>nH=
iU 6,B
//日志 8TB|Y
public static void log(String sMsg) QEt"T7a[/
{ GV1Ol^
System.err.println(sMsg); ]h`*w
} Bcv{Y\x;ko
nD eVYK
tP! %(+V
public static void log(int sMsg) v4|TQ8!wR
{ \v-I<"::
System.err.println(sMsg); s;oe Qa}TB
} 5<PNl~0
} lJFy(^KQG,
FNLS=4
?eX$Wc{
/* N(4y}-w$
**TestMethod.java @u/CNx,`X
*/ Jb*QlsGd
package NetFox; <]G'& iv>
o[Qb/ 7
tTTHQ7o*BD
public class TestMethod { F68eI%Y
PA ZjA0d
7$%G3Q|)L
public TestMethod() n^{h@u
{ ///xx/weblogic60b2_win.exe CQ6I4k
try{ 1K/ :
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VV1sadS:S`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }Em{?Hqy
SiteFileFetch fileFetch = new SiteFileFetch(bean); tc`3-goX
fileFetch.start(); L%$-?O|
} n7;jME/!
catch(Exception e){e.printStackTrace ();} D%3$"4M7!
,|yscp8
FD E?O]^
} y{3+Un
cOdRb=?9
U{ 0~&
public static void main(String[] args) p({@t=L3g
{ P,m+^,
new TestMethod(); #Swc>jYc
} .F@Lx45
} fh)eL<I
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