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)); OR\DTLIl
} ~r^5-\[hZ
for(int i=0;i<nEndPos.length-1;i++) t{SMSp
{ jD/7/G*
nEndPos = nStartPos[i+1]; P:(EU s}0
} >u5g?yzw
nEndPos[nEndPos.length-1] = nFileLength; P$18Xno{
} px|>v8
} LR3`=Z9
/*AJr
|vfujzRZ
//启动子线程 :,NFFN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |'c4er/;#
for(int i=0;i<nStartPos.length;i++) H5Ux.]y
{ _7lt(f[S
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M_h8#7{G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lC=N:=Mu
nStartPos,nEndPos,i); 1iJ0Hut}d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DhLr^Z!h3;
fileSplitterFetch.start(); NTm<6Is`
} OG`|td
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L/q]QgCoA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4YDT%_h0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "($Lx
nEndPos = " + nFileLength); jVad)2D
// fileSplitterFetch[nPos.length-1].start(); |Bx||=z`
eC6>yD6D
;Y'8:ncDn
//等待子线程结束 x0\e<x9s
//int count = 0; P>*Fj4Z~
//是否结束while循环 EqD^/(,L2
boolean breakWhile = false; 1l/AKI(!
|}K
D:wnO|:
while(!bStop) 9ZDVy7m\i-
{ kSB
write_nPos(); `d7gm;ykp
Utility.sleep(500); J| SwQE~
breakWhile = true; PXw| L
`"a? a5]k
Dv<wge`
for(int i=0;i<nStartPos.length;i++) 6xH;:B)d
{ $!!R:Wn/R
if(!fileSplitterFetch.bDownOver) )]%e
{ NWEhAj<w
breakWhile = false; Wrmgu}q
break; oW0gU?Rr)u
} HSNOL
} <57g{e0I
if(breakWhile) ,H>W:O
break; 807al^s x
b-PSm=`
q75ky1^1:
//count++; `9/0J-7*
//if(count>4) gs?8Wzh90*
// siteStop(); 5XDgs|8
} R]Hz8 _X
&=G)NeT_
:-z&Y492
System.err.println("文件下载结束！"); _B)s=Snx
} d$w(-tV42
catch(Exception e){e.printStackTrace ();} `M&P[.9Pz
} Cl,9yU)1n
S+r^B?a<oM
Q|?'(J+
//获得文件长度 sa*g
public long getFileSize() B`i$Wt<7
{ FC{})|yh }
int nFileLength = -1; tZbFvk2
try{ @Tm`d ?^
URL url = new URL(siteInfoBean.getSSiteURL()); V\0E=M*P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yO00I`5
httpConnection.setRequestProperty("User-Agent","NetFox"); 7'z(~3D
}`9jH:q-Z
tAERbiH
int responseCode=httpConnection.getResponseCode(); OZf6/10O/
if(responseCode>=400) S#tY@h@XV
{ msiu8E
processErrorCode(responseCode); [ 7g><
return -2; //-2 represent access is error jXixVNw
} 28a$NP\KW
{=67XrWN1
1c$vLo832
String sHeader; )n>+m|IqY(
DSvmVI
R:M,tL-l
for(int i=1;;i++) Tg0CE60"
{ L_Q S0_1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c+g@Z"es
//Utility.log(in.readLine()); ?F_)-
sHeader=httpConnection.getHeaderFieldKey(i); Ird|C[la
if(sHeader!=null) 2Q@Y^t
{ z8"7u/4v{
if(sHeader.equals("Content-Length")) l(!/Q|Q|
{ H>XFz(LWh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2o4^
break; lq>AGw
} V%*b@zv
} ?T!)X)A#
else "hQgLG
break; VL\t>n
} 1& ^?U{
} MjD75hIZ
catch(IOException e){e.printStackTrace ();} y t5H oy
catch(Exception e){e.printStackTrace ();} 36vgX=}
D=+NxR[
$!B}$I;cd
Utility.log(nFileLength); 69OF_/23
'V (,.'
<%P2qgz5
return nFileLength; ?6"{!s{v
} 4<gb36)|4
S6g<M5^R
G8J*Wnwu[K
//保存下载信息（文件指针位置） ;+/o?:AH
private void write_nPos() _>yoX
{ (Un_!)
try{ t9cl"F=
output = new DataOutputStream(new FileOutputStream(tmpFile)); `$TRleSi
output.writeInt(nStartPos.length); =d)-Fd2li
for(int i=0;i<nStartPos.length;i++) ._PzYE|m2
{ :O= \<t
// output.writeLong(nPos); :j^FJ@2_
output.writeLong(fileSplitterFetch.nStartPos); `5~3G2T
output.writeLong(fileSplitterFetch.nEndPos); AUe# RP
} n6<V+G)T
output.close(); .(CP. d
} {{yZ@>o6
catch(IOException e){e.printStackTrace ();} $I9qgDJ)
catch(Exception e){e.printStackTrace ();} 0#cy=*E
} [7FItlF%I
F4L;BjnJ
@]aOyb@
//读取保存的下载信息（文件指针位置） $*R/tJ.
private void read_nPos() C3NdE_E
{ ^-z=`>SrS"
try{ fw6UhG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cWyW~Ek
int nCount = input.readInt(); {gbn/{
nStartPos = new long[nCount]; }a AH
nEndPos = new long[nCount]; f"1>bW>R+
for(int i=0;i<nStartPos.length;i++) 0&_UH}10
{ sZGj"_-Hzu
nStartPos = input.readLong(); 03E4cYxt5
nEndPos = input.readLong(); 3jB$2:#
} b` Hz$8
input.close(); !`41q=r
} jO*l3:!~\
catch(IOException e){e.printStackTrace ();} ?`zXLY9q7
catch(Exception e){e.printStackTrace ();} +5VLw
} YQJ==C1
p~HW5\4
I$N8tn+E
private void processErrorCode(int nErrorCode) GaX[C<Wt
{ JRCrZW}
System.err.println("Error Code : " + nErrorCode); EnOU?D
} ^uv<6
JRo?s~Ih
^WBuMCe
//停止文件下载 ;qHOOT
public void siteStop() {pM?5"MMJ
{ [kE."#
bStop = true; 4jD2FFG- G
for(int i=0;i<nStartPos.length;i++) -'~LjA(
fileSplitterFetch.splitterStop(); 34\(7JO
Xd^\@
.9Y)AtJTS
} S[WG$
} o sKKt?^?
//负责部分文件的抓取 6G=j6gK%P
**FileSplitterFetch.java UTXSeNP
*/ sc,Xw:YO
package NetFox; kbM3
gz3pX#S
E Cyyl
import java.io.*; zOQ>d|p?X
import java.net.*; bV,}Pp+/"!
rRFhGQq1m
fW?o@vlO
public class FileSplitterFetch extends Thread { y*X_T,K8
n=[/Z!
9-MUX^?u
String sURL; //File URL JH7<
long nStartPos; //File Snippet Start Position W*2U="t
long nEndPos; //File Snippet End Position ght$9>'n
int nThreadID; //Thread's ID rS;Dmm
boolean bDownOver = false; //Downing is over yj\Nkh
boolean bStop = false; //Stop identical 1YH+d0UGn
FileAccessI fileAccessI = null; //File Access interface uCcYPvm
6Oy$gW)
0\eIQp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [sW3l:^
{ x9JD\vZ
this.sURL = sURL; :8OZ#D_Hl
this.nStartPos = nStart; &G-!qxe
this.nEndPos = nEnd; 'ET~
nThreadID = id; ,k;^G>< =
fileAccessI = new FileAccessI(sName,nStartPos);//定位 % yw?s0
} 6ZP"p<xX
3U0`,c\ao*
]iUxp+
public void run() B\XKw'
{ va0{>Dc+
while(nStartPos < nEndPos && !bStop) S Em Q@1
{ Ck)*&
LA}Syt\F
Kkm>e{0)AY
try{ 85LAYaw
URL url = new URL(sURL); ,Pdf,2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0"pAN[=K@
httpConnection.setRequestProperty("User-Agent","NetFox"); $adbCY\
String sProperty = "bytes="+nStartPos+"-"; )% ~OH
httpConnection.setRequestProperty("RANGE",sProperty); 3v1iy/ /
Utility.log(sProperty); ~=uWD&5B4
pu2tY7Ja
3`t%g[D1
InputStream input = httpConnection.getInputStream(); E2Q[ZoVS
//logResponseHead(httpConnection); '/^qJ7eb
6">+ ~ G
n$$SNWgM
byte[] b = new byte[1024]; "eB$k40-
int nRead; n[lJLm^(_C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w5Y04J
{ 7$CBx/X50)
nStartPos += fileAccessI.write(b,0,nRead); Ab{ K<:l
//if(nThreadID == 1) (>nGQS]H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X\{LnZ@r4
} U:^PC x`
%C|n9*
TFlet"ge=
Utility.log("Thread " + nThreadID + " is over!"); )48QBz?
bDownOver = true; {zQ8)$CQ
//nPos = fileAccessI.write (b,0,nRead); ;$.J3!
} 3G}x;Cp\D
catch(Exception e){e.printStackTrace ();} }fb#G<3
} D1zBsi94D
} $u]jy0X<Y;
3@dL/x4A
Q(wx nm
//打印回应的头信息 a_f~N1kq
public void logResponseHead(HttpURLConnection con) QbkLdM,S*
{ 7%Gwc?[x
for(int i=1;;i++) :XZU&Sr"
{ JtYP E?
String header=con.getHeaderFieldKey(i); ^o3"#r{:+
if(header!=null) l;R%= P?'F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HN=V"a
Utility.log(header+" : "+con.getHeaderField(header)); ,':fu
else \^L`7cBL
break; TC!Yb_H}gN
} $q6BP'7
} Ugu[|,
EMwS1~3dD
$WyD^|~SF
public void splitterStop() -JMdE_h
{ 5na~@-9p
bStop = true; Q sZx) bO
} C7lH]`W|/
zi|+HM
be]bZ 1f
} dgR g>)V
"& ])lz[u
$?Yry.2
/* `eE&5.
**FileAccess.java G`SUxhCk
*//文件访问(定位，写) Sj]T
package NetFox; diJLZikk
import java.io.*; Aydm2!l1
e@Fo^#ImDx
Wvbf"hq
public class FileAccessI implements Serializable{ LPZF)@|`
nygbt<;?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "'c A2~
RandomAccessFile oSavedFile; q$I;dOCJ,
long nPos; S>h;K`
3LAIl913
tjIl-IQ
public FileAccessI() throws IOException $bW3_rl%X
{ AqWUwK9T
this("",0); Huy5-[)15
} $G8E 3|k
AJh w
l==``
public FileAccessI(String sName,long nPos) throws IOException Sh/T,
{ DK$X2B"cV
oSavedFile = new RandomAccessFile(sName,"rw"); ~Mx!^
this.nPos = nPos; GR&z,
oSavedFile.seek(nPos); -8; 7Sp1
} I KqQ>Z-q~
4]yOF_8h
dYT%
public synchronized int write(byte[] b,int nStart,int nLen) wG~`[>y (
{ hlV=qfc
int n = -1; K~AR*1??[
try{ {9?JjA
oSavedFile.write(b,nStart,nLen); W=j[V Oq
n = nLen; \#f<!R4
} tXoWwQD;Y
catch(IOException e) kO,zZF&
{ Y'1S`.
e.printStackTrace (); wfNk=)^$
} zDw5]*R
[0(B>a3J
Zo|.1pN
return n; gYNjzew'
} !F1M(zFD
"Om=N@?
mR&H9NG
} -7*ET3NSI/
u])b,9&En
tasIDoo+!J
/* ur3(HL
**SiteInfoBean.java )Hpa}FGT
*/ ]ro*G"-_1#
package NetFox; Q~OxH'>>(
_oHNkKQ
wCr(D>iM
public class SiteInfoBean { vK9E
H=g`hF]`
/LvRP yj@
private String sSiteURL; //Site's URL Of"
private String sFilePath; //Saved File's Path ]b\yg2
private String sFileName; //Saved File's Name &7`^i.fh)
private int nSplitter; //Count of Splited Downloading File Jll-`b 1
V#XppYU
F ~^Jmp7Y
public SiteInfoBean() :<hXH^n
{//nSplitter的缺省值为5 6kNrYom
//default value of nSplitter is 5 EH256f(&
this("","","",5); j/fzzI0@
} `+o2DA)#(
n@C[@?D
W+PJZn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N>XS=2tzN
{ Y&S24aql
sSiteURL= sURL; )2bvQy8K
sFilePath = sPath; 8zRP(+&W
sFileName = sName; PmKeF}
this.nSplitter = nSpiltter; ;D:9+E<>a
Y0x%sz5
P{wF"vf
} Y~L2
SZ,YS 4M
\#Pfj&*
public String getSSiteURL() In18_bc
{ +89*)pk
return sSiteURL; w8MG(Lq1"
} P(+&OoY2
T)H{
x4E7X_
public void setSSiteURL(String value) XZ^^%*ew
{ l|kSsP:GO
sSiteURL = value; ~]nSSD)\
} L<ue$'
wB!Nc Y\p
f@Zszt
public String getSFilePath() ^; )8VP6
{ Cj{1H([-
return sFilePath; ] Hztb
} (NF~Ck$#q
S7/eS)SQR
[8T^@YN
public void setSFilePath(String value) 3HcQ(+Z
{ M<kj_.
sFilePath = value; X!9 B2w
} C~o7X^[R\
mF,Y?ax
whi`Z:~
public String getSFileName() f;W|\z'
{ Rm255zp
return sFileName; :lf+W
} TFkZpe;
BqD'8zLD
ki?S~'a
public void setSFileName(String value) e\!0<d
{ 19E8'@
sFileName = value; qz0;p=$8Z
} 57umx`m
+trC,D
E5I"%9X0H
public int getNSplitter() /v-6WSN
{ +l9!Fl{MK\
return nSplitter; n1ly y0%u
} n%-R[vW
BD_Iz A<wK
3%E }JU?MM
public void setNSplitter(int nCount) lku[dQdk
{ 6{n!Cb[e
nSplitter = nCount; 62k^KO6Y
} 9Iwe2lu
} mH%yGBp_
M>~Drul
.1KhBgy^K
/* pWK(z[D
**Utility.java *h!28Ya(~
*/ ]xRM&=)<
package NetFox; (tIo:j
nExU#/*~^
'ig&$fzb
public class Utility { ,z;cbsV-{
CE#gfP
N/%WsQp
public Utility() ^@3sT,M,S
{ #gz M|
Sdt`i
QZ6D7tUc8
} l_o@miG/
4]?<hH9
//线程睡眠 2%LLSa
public static void sleep(int nSecond) 7 n8"/0kc:
{ Yw^m
try{ Q.l}NtHwV
Thread.sleep(nSecond); yXSFjcoB
} h"X;3b^ m
catch(Exception e) ,]9P{k]O
{ % tS,}ze
e.printStackTrace (); AL9chYP}/
} R3x3]]D
} w65K[l;2
11o.c;
//日志 ?}wk.gt>
public static void log(String sMsg) 0?s|i :
{ OLyf8&AU@
System.err.println(sMsg); 1eS&&J5
} B<5R
yA)/Q Yge
|iakz|])
public static void log(int sMsg) ur)9x^y
{ (SpX w,:
System.err.println(sMsg); Cn,d?H
} Gr*r=s
} CAfGH!l!
E{XH?_xo
wxKX{Bs
/* SF7\<'4\N
**TestMethod.java `, OG7hg
*/ ff]6aR/ UQ
package NetFox; "|EM;o
'~5LY!H(pT
%Qmn-uZ
public class TestMethod { }tRm]w
;Y00TGU
CS2Bo
public TestMethod() e%svrJ2
{ ///xx/weblogic60b2_win.exe ~-ia+A6GIV
try{ ,k24w7K%d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s3z$e+A8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y&6FybIz
SiteFileFetch fileFetch = new SiteFileFetch(bean); &*##bA"!B
fileFetch.start(); 6V$Avg\6\
} `.E[}W
catch(Exception e){e.printStackTrace ();} \HqNAE2T
Z-^LKe
Z/W:97M
} t>L;kRujVJ
@P#N2:jwj
=m!-m\B/
public static void main(String[] args) pV9IHs}
{ Yrb{ByO&
new TestMethod(); }u\])I3
} SON-Z"v
} y`VyQWW
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