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)); >Hnm.?-AWl
} ?b+Y])SJK
for(int i=0;i<nEndPos.length-1;i++) _{jC?rzb
{ un 5r9
nEndPos = nStartPos[i+1]; U 3< 3T
} j,.M!q]
nEndPos[nEndPos.length-1] = nFileLength; Mc,|C)
} tpGT~Y(
} _8.TPB]no
=6~
r.eK;
//启动子线程 ],weqs
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~3.*b%,
for(int i=0;i<nStartPos.length;i++) KM;H '~PZi
{ 2 q4p-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `$/a-K}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4v`/~a
nStartPos,nEndPos,i); vQ}ZfP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HFFG4'
fileSplitterFetch.start(); +ALrHFG
} `TPIc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 44u)F@)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PRU&y/zZmG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 486\a
nEndPos = " + nFileLength); i3eF_
// fileSplitterFetch[nPos.length-1].start(); He=C\"
M)#9Q=<
}!_z\'u
//等待子线程结束 3*<@PXpK&
//int count = 0; Aars\
//是否结束while循环 v;\cM/&5
boolean breakWhile = false; 8r(awp
``CM7|)>`
8|zavH#P
while(!bStop) q~}oU5
{ U3N d\b'0
write_nPos(); Hl}lxK,]
Utility.sleep(500); #r#[&b
breakWhile = true; "d)YqQ
![%wM Pp
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for(int i=0;i<nStartPos.length;i++) 1Of(O!
{ 6]iU-k0b
if(!fileSplitterFetch.bDownOver) Kzn1ct{65!
{ uZL]mwkj]
breakWhile = false; inU5eronuj
break; k( Sda>-
} F:m6Mf7L
} 9HJYrzf{%
if(breakWhile) J+t51B(a
break; HVus\s\&y%
b3%x&H<j
Pp }Z"
//count++; 3g4=as4w
//if(count>4) )'m;a_r`
// siteStop(); ow \EL
} KfjWZ4{v
#;!@Pf
48wt
System.err.println("文件下载结束！"); he~8V.$
} ^>E>\uz0v
catch(Exception e){e.printStackTrace ();} `n>|rd
} fof}I:vO
bIGcszWr
kKlNhP(
//获得文件长度 _p8u &TZ
public long getFileSize() eHvUgDt
{ P-B5-Nz
int nFileLength = -1; 0JtM|Mg
try{ BeFyx"NBg
URL url = new URL(siteInfoBean.getSSiteURL()); f5F-h0HF`[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B0yJ9U= Fj
httpConnection.setRequestProperty("User-Agent","NetFox"); eikZ~!@
<B>qEa_I
+-qk\sQ
int responseCode=httpConnection.getResponseCode(); WD\Yx~o
if(responseCode>=400) e'uC:O.u
{ W#U|;@"
processErrorCode(responseCode); 0p.MH~mx
return -2; //-2 represent access is error :=*G7ZyW$
} Wi=zu[[qc
q`mxN!1[
_'w:Sx?d7
String sHeader; d;>G
!4Zy$69R
}&+,y<>
for(int i=1;;i++) #C }+
{ dBA&NW07
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); FR6 W-L
//Utility.log(in.readLine()); g"" 1\rc=
sHeader=httpConnection.getHeaderFieldKey(i); 7~J>Ga
if(sHeader!=null) .aO6Y+Y
{ rZwSo]gp
if(sHeader.equals("Content-Length")) >{{ds--
{ P7W|e~]Yq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'qEw]l
break; Ps.xY;Y
} !S&/Zp
} _R(ZvsOZ
else 9Vq
break; ,j>FCj>
} Z[VrRT,\c
} !GvT{
catch(IOException e){e.printStackTrace ();} 6 8n ;#-X
catch(Exception e){e.printStackTrace ();} ;39a`
2He R1m<
W=EcbH9/.)
Utility.log(nFileLength); IT=y+
|APOTQV
zQ:nL*X'Z"
return nFileLength; JE{cZ<NNH
} msCz\8Xd
g&$5!ifgi
[4C_iaE
//保存下载信息（文件指针位置） (rJ-S"^u
private void write_nPos() =Bc{0p*
{ bxPa|s?
try{ sF)$<[w
output = new DataOutputStream(new FileOutputStream(tmpFile)); QZ(O2!Mg
output.writeInt(nStartPos.length); >pZ_
for(int i=0;i<nStartPos.length;i++) :9L}jz
{ ; Yc\O:Qq
// output.writeLong(nPos); ^m D$#
output.writeLong(fileSplitterFetch.nStartPos); mpD.x5jm<
output.writeLong(fileSplitterFetch.nEndPos); 4J`-&05O
} ~}p k^FA
output.close(); !7~4`D c6U
} Fv,c8f
catch(IOException e){e.printStackTrace ();} c]VK%zl
catch(Exception e){e.printStackTrace ();} 9wc\~5{li
} >Giw\|:f(
3,i`FqQa
i@P=*lLD
//读取保存的下载信息（文件指针位置） GCQOjqiR
private void read_nPos() jJYCGK$=
{ N1g;e?T':
try{ qooTRqc#,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MW^FY4V1m
int nCount = input.readInt(); S9[Up}`
nStartPos = new long[nCount]; tculG|/
nEndPos = new long[nCount]; S+6YD0
for(int i=0;i<nStartPos.length;i++) &{WEtaXaa
{ 2>x[_
nStartPos = input.readLong(); Z$Ps_Ik
nEndPos = input.readLong(); v(O@~8(I
} v(sS$2J|}
input.close(); T|oDJ]\J
} ;$!0pxL)s
catch(IOException e){e.printStackTrace ();} `ALQSo~l
catch(Exception e){e.printStackTrace ();} )"P.n-aF
} 1Ogtzf
EG=U](8T
hZe9Y?)
private void processErrorCode(int nErrorCode) -xH3}K%
{ q_;#EV
System.err.println("Error Code : " + nErrorCode); z}VCiS0
} bw#\"uJ
rA_r$X
hoPh#? G
//停止文件下载 ^=cXL
public void siteStop() nM$-L.dG
{ K}S=f\Q]
bStop = true; %HZ!s `w_
for(int i=0;i<nStartPos.length;i++) qP%[nY
fileSplitterFetch.splitterStop(); -Xgup,}?
giddM2'
@yPI$"Ma
} %%O_:@9x,
} 79lG~BGE
//负责部分文件的抓取 !Nhq)i
**FileSplitterFetch.java oB}rd9
*/ W9SEYkg
package NetFox; FRE${~Xd
?v@q&
a)L=+Z
import java.io.*; E[_-s
import java.net.*; $J:~jY/J
dI8y}EbE~
TlBu3z'P
public class FileSplitterFetch extends Thread { z?_5fte`
}xzbg
Vuo 8[h>
String sURL; //File URL }JWk?
long nStartPos; //File Snippet Start Position O~g0R6M6e
long nEndPos; //File Snippet End Position h@?BA<'S
int nThreadID; //Thread's ID G Q+g.{c
boolean bDownOver = false; //Downing is over T/l2B1
boolean bStop = false; //Stop identical [+$o`0q;N?
FileAccessI fileAccessI = null; //File Access interface !g-19at
.7GAGMNS
d`+cNKf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O/Wc@Ln
{ v:] AS:
this.sURL = sURL; )wYbcH
this.nStartPos = nStart; A|U_$!cLZ
this.nEndPos = nEnd; HPR*:t
nThreadID = id; E :Y *;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ijj]_V{,
} lFLiW
BK:S:
7e-l`]
public void run() H0B"?81
{ nMHs5'_y
while(nStartPos < nEndPos && !bStop) M9b_Q
{ ^m:?6y_uw
Ge;plD-f
_,4f z(
try{ 4RqOg1
URL url = new URL(sURL); u{ .UZTn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ' RjFWHAp
httpConnection.setRequestProperty("User-Agent","NetFox"); ^25[%aJI
String sProperty = "bytes="+nStartPos+"-"; ^4yFLqrC
httpConnection.setRequestProperty("RANGE",sProperty); kw!1]N
Utility.log(sProperty); %h%^i
)LwB
{ O*maE"
InputStream input = httpConnection.getInputStream(); @`ttyI^1f
//logResponseHead(httpConnection); h&vq}
%!HmtpS
)S|}de/a2
byte[] b = new byte[1024]; Gu:aSb
int nRead; 'qhA4W9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P$\vD^
{ V<@]Iv
nStartPos += fileAccessI.write(b,0,nRead); &k?Mt#J
//if(nThreadID == 1) Rd5r~iT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SA|f1R2uS
} #{l+I(M
l 49)Cv/
,bCPO`45
Utility.log("Thread " + nThreadID + " is over!"); @qH<4`y.^
bDownOver = true; lV^sVN Z]
//nPos = fileAccessI.write (b,0,nRead); J+LFzl07q
} /9WR>NUAO
catch(Exception e){e.printStackTrace ();} ^=wG#!#V"1
} -iS\3P.
} +aV>$Y
Eq.?Ga
ewk62{
//打印回应的头信息 >"S'R9t
public void logResponseHead(HttpURLConnection con) 0%+TU4Xx
{ l0b Y
for(int i=1;;i++) xk}YeNVj
{ /"Om-DK%
String header=con.getHeaderFieldKey(i); VzMoWD;
if(header!=null) Kig.hHj@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~^IS{1
Utility.log(header+" : "+con.getHeaderField(header)); ^ow[XEB%
else >\$qF
break; e0*',
} \p.Byso,
} ID5?x8o#k
6$b"tdP
W9Bl'e
public void splitterStop() ;vF8V`f
{ v)+wr[Qs
bStop = true; lb&tAl"D
} W==HV0n
gV!Eotq
Sy'/%[+goJ
} f| 3`8JU
VE6T&fz`
us4.-L
/* )"jG)c^1*
**FileAccess.java <2ffcBv
*//文件访问(定位，写) U{LDtn%@h6
package NetFox; n@5pS3qZ
import java.io.*; @|%t<{y^I
N*lq)@smq
[lQp4xgxi
public class FileAccessI implements Serializable{ g 6>RyjN
?qw&H /R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q uv`~qn
RandomAccessFile oSavedFile; x7l)i!/$
long nPos; H<%7aOwO2
NV*aHci
v.cB3/$z
public FileAccessI() throws IOException :{LVS nG
{ 5 &-fX:/
this("",0); _"a(vfl#
} @p|[7'
{.H}+@0
68Wm=j.m
public FileAccessI(String sName,long nPos) throws IOException vV#Jl) A
{ Trbgg
oSavedFile = new RandomAccessFile(sName,"rw"); t{!}^{ "5
this.nPos = nPos; -CT?JB
oSavedFile.seek(nPos); ]Vl*!,(i
} ;{q7rsE
,, ]y 8P
A:p7\Kp;5}
public synchronized int write(byte[] b,int nStart,int nLen) R7x4v
{ u+[ZWhKUp
int n = -1; = Yh>5A
try{ n|SsV
oSavedFile.write(b,nStart,nLen); f Nm Sx
n = nLen; 8Th|'
} L;fhJ~r
catch(IOException e) b,KQG|k
{ Nypa,_9}
e.printStackTrace (); 7I^(vQ
} ,Ztj
?%;7k'0"
Cj_cu
return n; 3UslVj1u
} -AD3Pd|Y[
>Ah [uM
}4#%0x`w
} +7^%fX;3pW
r<UZ\d -
_9Iz'-LgB
/* Wl;F]_|*(
**SiteInfoBean.java tP"C>#LO
*/ dL |D
package NetFox; qI^6}PB
-PBm@}*
&h`s:Y
public class SiteInfoBean { !-U5d9!
3RXq/E
x`WP*a7Fk]
private String sSiteURL; //Site's URL ",w@_}z:
private String sFilePath; //Saved File's Path C6M|A3^T
private String sFileName; //Saved File's Name M//q7SHh
private int nSplitter; //Count of Splited Downloading File V~+Oil6sa
w;&J._J
=n cu#T]
public SiteInfoBean() #i%it
{//nSplitter的缺省值为5 -,uTAk0+@
//default value of nSplitter is 5 2h IM!wQ
this("","","",5); 7!]$XGz[
} 8uP,#D<wZ
mHM38T9C%
#@w8wCj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Dwj!B;AZ_
{ Xjw>Qws
sSiteURL= sURL; dPc*!xrq
sFilePath = sPath; 2RFYnDN
sFileName = sName; 3%bCv_6B
this.nSplitter = nSpiltter; g j8rrd|
YiJnh47
E/v.+m
} <1YINkRz
tSaLR90Y6
$5yH(Z[[
public String getSSiteURL() |L}zB,
{ ,)TtI~6Q
return sSiteURL; ]P;uQ!
} %PRG;kR
#` Q3Z}C
n+QUT
public void setSSiteURL(String value) t~U:Ea[gd
{ 8n+&tBq1
sSiteURL = value; HY0q!.qog
} |5oK04<
N[~{'i
/j/,@,lw7z
public String getSFilePath() *oopdGue
{ 0zQ"5e?qy
return sFilePath; ;\ ^'}S|3Z
} q,`"Z)97
Yv<'QC
K2$ fKju
public void setSFilePath(String value) Fa<>2KkOr
{ 4<}!+X7m
sFilePath = value; uu ahR
} hgIqr^N9
;;e\"%}@=q
KZy2c6XO;
public String getSFileName() g_X-.3=2K
{ XJg8-)T#
return sFileName; CD]hi,B_J
} sZe$?k|
Lzmdy0!'
9 5bi W
public void setSFileName(String value) loRT+u$&
{ mm}y/dO~}
sFileName = value; bfo..f-0/Y
} U*sjv6*T
UWU(6J|Fk
gu?e%]X3
public int getNSplitter() Nq]8p =e
{ ba5,?FVI~
return nSplitter; WX"iDz.
} h/oRWl0r
OBb m?`[
Z9 z!YaOL
public void setNSplitter(int nCount) BF^dNgn+%K
{ 8^IV`P~2M
nSplitter = nCount; Ibf~gr(j
} 5Zf^cou
} G)|Xj70
Eep~3U
oW}nr<G{<
/* yMG(FAyu
**Utility.java }K.Rv(m
*/ is~"yE7
package NetFox; ]& 8c 45c
dU}Cb?]7s
1Kjqs)p^
public class Utility { QhhL_vP
#B!|sXC
U g:
public Utility() SFu]*II;{
{ ,`Keqfx
&Fiesi!tET
{EfA#{x
} J&2J6Eq
!>:SPt l
//线程睡眠 XF&_**0n
public static void sleep(int nSecond) +>&i]x(b
{ bm*.*A]
try{ XS}-@5TI
Thread.sleep(nSecond); uTdx`>M,O
} r|63T%q!
catch(Exception e) "S]G+/I|iw
{ {#.<hPXn
e.printStackTrace (); XDYQV.Bv
} zfD@/kU
} lak,lDt]
ew \WV"
//日志 /1v:eoF;
public static void log(String sMsg) "38L ,PW0Z
{ VFrp7;z43
System.err.println(sMsg); d5>EvK U
} v.&c1hKHb
z~-(nyaBS
q@G}Hjn
public static void log(int sMsg) xnC:?d
{ gg/ts]$
System.err.println(sMsg); **\?-*c=U
} MgP&9
} [8<0Q_?,
a/v]E]=qI
f|=u{6
/* m^\&v0
**TestMethod.java BoQ%QV69%
*/ ;"2VU"
package NetFox; I94-#*~I
(Hmm^MV)
diNAT`|?#
public class TestMethod { }$'XV.
]bAVOKm-
h56Kmxxk
public TestMethod() obGhO
{ ///xx/weblogic60b2_win.exe [K@(,/$
try{ lX-i<0`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,>01Cs=t8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %-]a[qf3
SiteFileFetch fileFetch = new SiteFileFetch(bean); u(fZ^
fileFetch.start(); gkX7,J-0
} mlCBstt{
catch(Exception e){e.printStackTrace ();} (t\U5-w
6uv~.-T<l
-$kIVh
} 5]GgjQ
ZPY&q&R
7AS_Aw1L
public static void main(String[] args) {=\Fc`74
{ L,.AY?)+7
new TestMethod(); qo$ls\[X
} *7-rm
} jV9oTH-
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