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)); ?@"F\Bv<h
} yPG,+uQ$.
for(int i=0;i<nEndPos.length-1;i++) wZ7Opm<nt
{ _U}pdzX?
nEndPos = nStartPos[i+1]; A$gP: 1&m
} Rlc$2y@pU
nEndPos[nEndPos.length-1] = nFileLength; 6Y4sv5G
} $10"lM[
} /VFh3n>I2
o^P/ -&T
ZmSe>}B=
//启动子线程 G9'Wo.$ t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;T1OXuQ
for(int i=0;i<nStartPos.length;i++) X|!VtO
{ $ M?VJ\8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *o<zo `
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wlc Cz
nStartPos,nEndPos,i); gA0:qEL\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w|$i<OIi)
fileSplitterFetch.start(); i("ok
} f' |JLhs
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TEQs\d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lYz{#UX}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m2wGg/F5
nEndPos = " + nFileLength); _P6e%O8C#
// fileSplitterFetch[nPos.length-1].start(); l/?Jp+]
%JUD54bBt
5>z`==N)
//等待子线程结束 8nzDLFxp_
//int count = 0; m-V_J`9"
//是否结束while循环 >bQ'*!
boolean breakWhile = false; a,<l_#'
J1P jMb}
/)6+I(H
while(!bStop) quXL'g
{ VX+:k.}
write_nPos(); f(}?Sp_
Utility.sleep(500); NDsF<2A4
breakWhile = true; X2CpA;#;7l
~mAv)JK
vjNP
for(int i=0;i<nStartPos.length;i++) jz CA2N%
{ 4%k{vo5i
if(!fileSplitterFetch.bDownOver) }N@8zB~X
{ AlZ]UGf^
breakWhile = false; fpd4 v|(
break; a=m4)tjk
} ?T.' q
} %x(||cq
if(breakWhile) Tj0qq.
break; ~kHWh8\b:
0?@;zTE0
bH6i1c8
//count++; 4KSZ;fV6/
//if(count>4) ;UU`kk
// siteStop(); ck0K^o v
} FU]jI[
p./9^S
B=vBJC)
System.err.println("文件下载结束！"); V)|]w[(Y
} HLYog+?
catch(Exception e){e.printStackTrace ();} .7GTL
} .J?cV;:`
o03Y w)*
P_(QG 6
//获得文件长度 },r9f MJ
public long getFileSize() _x+)Tv
{ CEQs}bz
int nFileLength = -1; JU>F&g/|
try{ 'YFy6rds
URL url = new URL(siteInfoBean.getSSiteURL()); +!"GYPUXy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0oT~6BGm
httpConnection.setRequestProperty("User-Agent","NetFox"); <c;U 0! m
[2*?b/q3J
_+B{n^ {
int responseCode=httpConnection.getResponseCode(); ?$v*_*:2h
if(responseCode>=400) E@.daUoB
{ 9E`Laf
processErrorCode(responseCode); O0`o0!=P
return -2; //-2 represent access is error <m"fzT<"
} zDD
H6o_*Y
}BFX7X
String sHeader; 7+'&(^c
zCz"[9k
HpCTQ\H
for(int i=1;;i++) 2!kb?
{ h^ o@=%b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5rX_85]
//Utility.log(in.readLine()); l&JV.}qGB8
sHeader=httpConnection.getHeaderFieldKey(i); 3ncL351k
if(sHeader!=null) \+iZdZD
{ rS|nO_9f
if(sHeader.equals("Content-Length")) IuV7~w
{ NCX`-SLv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zb&5)&'X
break; i>j(Dsv
} \&XtPQ
} c^F@9{I
else jNbU{Z%r
break; ^55q~DP}>
} 9*Z!=Y#4,
} vV PK
catch(IOException e){e.printStackTrace ();} 8T523VI
catch(Exception e){e.printStackTrace ();} Q8h0:Q
q1Sr#h|
dy"7Wl]hi7
Utility.log(nFileLength); 9EFQo^ E
O\X=vh/D
qu`F,OG
return nFileLength; r]3v.GZy
} MkK6.qV\z
r-e-2y7
K^m`3N"
//保存下载信息（文件指针位置） M&SY2\\TB
private void write_nPos() 2Q;g|*]
{ KFhnv`a.0
try{ j=kz^o~mH
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZCAg)/
output.writeInt(nStartPos.length); ./qbWr`L
for(int i=0;i<nStartPos.length;i++) 7X{@$>+S
{ WupONrH1e
// output.writeLong(nPos); $?*XPzZ
output.writeLong(fileSplitterFetch.nStartPos); Q$^)z_jai
output.writeLong(fileSplitterFetch.nEndPos); -n"7G%$M
} w678
output.close(); ?{]"UnyVE*
} Yc`PK =!l
catch(IOException e){e.printStackTrace ();} $aC%&&+wG
catch(Exception e){e.printStackTrace ();} {36QZV*P
} BbG=vy8'l
o>^@s4t
1$n!Lj=5
//读取保存的下载信息（文件指针位置） M2Zk1Z
private void read_nPos() ~P,@">}
{ n2N:rP
try{ <Kk[^.7C;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D6fGr$(N%
int nCount = input.readInt(); BJP^?FUd=,
nStartPos = new long[nCount]; }$oZZKS
nEndPos = new long[nCount]; \R.Fmeko
for(int i=0;i<nStartPos.length;i++) ,<O|#`?"@G
{ CyKupJ.Fq
nStartPos = input.readLong(); z{(c-7*
nEndPos = input.readLong(); M?v`C>j
} wDt9Lf O
input.close(); 82P#C4c+d
} $_+.D`vx`
catch(IOException e){e.printStackTrace ();} g0k{b
catch(Exception e){e.printStackTrace ();} rd ]dDG
} lEC91:Jyt
g{e@I;F
]L;X Aj?
private void processErrorCode(int nErrorCode) f)#nXTXeC
{ -~TgA*_5]
System.err.println("Error Code : " + nErrorCode); |>v8yS5
} seS)`@n
i:sb_U+M
eMOnzW|h
//停止文件下载 }kF*I@:g
public void siteStop() mNQ*YCq.
{ ?{(Jy*
bStop = true; =SK{|fBB
for(int i=0;i<nStartPos.length;i++) *kq>Z 06'i
fileSplitterFetch.splitterStop(); &\5%C\0Z<
df8aM<&m3
vq8&IL
} X8~gLdv8
} I,7n-G_'
//负责部分文件的抓取 oLc
**FileSplitterFetch.java u;/<uV3
*/ KY9&Ky+2B
package NetFox; s-e<&*D[
VI;)VJbq
EViDMp"
import java.io.*; .]LP327u
import java.net.*; wh#x`Nc
MB"<^ZX
/rzZU}3[
public class FileSplitterFetch extends Thread { @YI-@
BE,H`G #h
lQt* LWd[
String sURL; //File URL (R^Ca7F
long nStartPos; //File Snippet Start Position A08{]E#v>
long nEndPos; //File Snippet End Position L=)Arj@q
int nThreadID; //Thread's ID X0BBJ(e
boolean bDownOver = false; //Downing is over Vbp`Rm1?
boolean bStop = false; //Stop identical [' cq
FileAccessI fileAccessI = null; //File Access interface (k<__W c_t
(T8dh|
X@^"@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N6uKFQL:{
{ 4L/8Hj#g
this.sURL = sURL; (E<QA
this.nStartPos = nStart; /u pDbP.O
this.nEndPos = nEnd; h%!N!\
nThreadID = id; YnwP\Arfq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r1AG1Y
} `t Zw(Z=h
}Oe9Zq
!~a1xI~s
public void run() ^<v]x; 3
{ S1E=EVG
while(nStartPos < nEndPos && !bStop) V"W)u#4,
{ *S\/l-D
:'K%&e?7s
$#HUxwx4
try{ Sj9NhtF]f
URL url = new URL(sURL); Z)dE#A_X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hgI;^ia
httpConnection.setRequestProperty("User-Agent","NetFox"); |C3~Q{A
String sProperty = "bytes="+nStartPos+"-"; {on+ ;,
httpConnection.setRequestProperty("RANGE",sProperty); Jsw%.<
Utility.log(sProperty); Bw*6X`'Q
/]hE?cmj
5 $: q
InputStream input = httpConnection.getInputStream(); YY9Ub
//logResponseHead(httpConnection); ;eiqzdP
)NCSO b
Qhsk09K_=4
byte[] b = new byte[1024]; 6^vHFJ$
int nRead; U=>4=gsG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z*M-PaU}
{ sI#r3:?i
nStartPos += fileAccessI.write(b,0,nRead); TptXH?
//if(nThreadID == 1) ="AJ&BqHd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <:Z-zQp)?
} 93fClF|@
V8IEfU
Q0-}!5`E1$
Utility.log("Thread " + nThreadID + " is over!"); $+Zj)V(
bDownOver = true; N83g=[
//nPos = fileAccessI.write (b,0,nRead); JN<IMH
} @DK;i_i
catch(Exception e){e.printStackTrace ();} 0OPpALl
} [XDr-5Dm
} #`b5kqQm
k5TPzm=y{
X7{ h/^
//打印回应的头信息 X)k+BJ
public void logResponseHead(HttpURLConnection con) zx=AT
{ M`gr*p
for(int i=1;;i++) 5Q.z#]Lg
{ <o.?T*Q9
String header=con.getHeaderFieldKey(i); O*y@4AR"S
if(header!=null) dRPX`%J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &~a/Upz0]_
Utility.log(header+" : "+con.getHeaderField(header)); 6/&aBE=
else `6`oLu\l
break; >2@ a\
} ;OY*`(Id
} ;'xd8Jf
X/-u$c
Q2HULz{
public void splitterStop() U8s&5~IPn
{ bsgrg
bStop = true; p@bcf5'
} i0e aBG]I
0F|DD8tHR
Q2 @Ugt$
} ? bnhx
4.}J'3 .
z8\;XR
/* Ss c3uo0
**FileAccess.java 2$%E:J+2:$
*//文件访问(定位，写) @N,I}_9-
package NetFox; okv`v ({
import java.io.*; Fu6~8uDV{{
CxW-lU3G`
nlaeo"]
public class FileAccessI implements Serializable{ ECF \/12
Vs~!\<?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rP7~R
RandomAccessFile oSavedFile; t_Rpeav
long nPos; /pOK4"
*>f-UNV
KWB;*P C^
public FileAccessI() throws IOException #I|jFn9
{ b+3QqbJ[F
this("",0); I]OVzM
} E]26a,^L
b+qdl`Vd
A-XWG9nL
public FileAccessI(String sName,long nPos) throws IOException t:<dirw,o
{ f*Dy>sw
oSavedFile = new RandomAccessFile(sName,"rw"); [r"`rBw
this.nPos = nPos; ~Q/G_^U:
oSavedFile.seek(nPos); tW#=St0<.o
} j/Rm~!q
ZQQ0}
f}U@e0Lsb
public synchronized int write(byte[] b,int nStart,int nLen) %HK\
{ {Y#$
int n = -1; rS/}!|uAu
try{ 8>y!=+9_
oSavedFile.write(b,nStart,nLen); ?E88y
n = nLen; _6,Tb]
} 9X6l`bo'
catch(IOException e) Jf|6 FQo&
{ eX9Hwq4X44
e.printStackTrace (); eaGd:(
} 5$C]$o}
M7 Z9(3Va
[J71aH
return n; |rg4j
} }3&~YBx;:
#0wH.\79
%Yi^{ZrM
} pg;y\}
2|C(|fD4
"/MA.zEl0,
/* v1Wz#oP
**SiteInfoBean.java 16N+
*/ WMw]W&
package NetFox; 4`Z8EV
|-SImxV
-Bl!s^-'
public class SiteInfoBean { *U69rbYI
vQiKpO*
= g[Cs*
private String sSiteURL; //Site's URL bEz1@"~ p
private String sFilePath; //Saved File's Path Zg#VZg1 2
private String sFileName; //Saved File's Name h72#AN
private int nSplitter; //Count of Splited Downloading File 78[5@U
0nbQKoF
*>,CG:`D
public SiteInfoBean() V<+=t{
{//nSplitter的缺省值为5 j~a"z40
//default value of nSplitter is 5 6YCFSvA#/
this("","","",5); [c=T)]E1
} n6f
5sc`L
S`qa_yI)Ed
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n,E=eNc
{ |VPJaiC~
sSiteURL= sURL; vS$_H<;P
sFilePath = sPath; Mx<?c
sFileName = sName; KS6H`Mm}/
this.nSplitter = nSpiltter; UD@u hL
c+^#(OB
_CDl9pP36#
} 4tb y N
q0l=S+0
aN/0'V|&ym
public String getSSiteURL() }wh sZ
{ =/b WS,=
return sSiteURL; #r ;;d(
} 10 D6fkjf
GvCB3z
8 FqhSzw
public void setSSiteURL(String value) 1sT%g}w@|
{ foOwJ}JU
sSiteURL = value; x/pM.NZF1
} }bg_?o;X}
=Bq3O58+
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public String getSFilePath() +TQMA>@g<
{ !k= ~5)x
return sFilePath; TL?(0]Hfe
} 2unaK<1s
m<DiYxK
y ;$8C
public void setSFilePath(String value) WjrUns
{ CfWtCA
sFilePath = value; %bp8VR sY
} 7K|: 7e(
F{g^4
{4@+ 2)l
public String getSFileName() *nPB+@f
{ DD4fV`:kG
return sFileName; [= GVK
} >Mzk;TM
}c"1;C&{
jv C.T]<B
public void setSFileName(String value) .=nx5yz
{ ![{>$Q?5
sFileName = value; ;B'5B]A3
} NX?IM8\t
Y)-)owx7
.[1"3!T
public int getNSplitter() ygvX}q
{ l^@!,Z
return nSplitter; Eep*,Cnt0
} eoC@b/F4
#ZPU.NNT?
pnvHh0ck_
public void setNSplitter(int nCount) )<kId4E
{ ;-OnCLr
nSplitter = nCount; VGVZ`|
} [CBhipoc
} QBNnvg4v
b~1]}9TJ
}nQni?
/* 0!:1o61
**Utility.java &7{/ x~S{
*/ U8T"ABvFP
package NetFox; b* QRd
/%#LA
=`b/ip5
public class Utility { 4rmSo^vK
Gl1Qbd0
7.r}98V
public Utility() Aj9Onz,Lg
{ : *~}\M*
wO&edZ]zb^
T\G2B*fGd
} ),<E-Ub
`v1Xywg9P
//线程睡眠 [F^qa/vJ10
public static void sleep(int nSecond) :`9hgd/9
{ [BH^SvE
try{ jWg7RuN
Thread.sleep(nSecond); }SdI _sLe
} AX Y.80+
catch(Exception e) T4OH,^J
{ = }&@XRLJ
e.printStackTrace (); ]y4(WG;:
} 3c"$@W:>
} g=*`6@_=
N34.Bt
//日志 #SHmAB
public static void log(String sMsg) Xm|Uz`A;
{ f1a >C
System.err.println(sMsg); 3H_mR j9th
} y;!qE~!3
\WDL?(G<
aAlES< r
public static void log(int sMsg) )wmG&"qsP
{ Lv`*+;1K
System.err.println(sMsg); B]`!L/
} aw0;
} & *^FBJEa.
b.`<T"y
;{n@hM*O
/* eb])=
**TestMethod.java .HM1c
*/ Y:~A-_
package NetFox; l1_Tr2A}7/
UN~dzA~V
X>[x7t:
public class TestMethod { ZfpV=DU
r((2.,\Z
B@:c8}2.
public TestMethod() +0w~Skd,
{ ///xx/weblogic60b2_win.exe a?zn>tx
try{ >q'xW=Y j\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NZJ:@J=-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jm-J_o;}z6
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2k }:)]m
fileFetch.start(); ^4+ew>BLSv
} ;g3z?Uz)
catch(Exception e){e.printStackTrace ();} d},IQ,Az:Z
lZY0A#
AoaRlk-#
} E&\dr;{7
>@NH Al
uhyw?#f
public static void main(String[] args) 0!D,74r
{ Quc,,#u
new TestMethod(); yGNZw7^(
} uCc.dluU
} ;XJK*QDN
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