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)); 9.xb-m7
} .feB VRg
for(int i=0;i<nEndPos.length-1;i++) ;m] nl_vg
{ W2h*t"5W
nEndPos = nStartPos[i+1]; 78]*Jx>L
} a9&[Qv5-/
nEndPos[nEndPos.length-1] = nFileLength; \roJf&O }
} O:I]v@
} *# <%04f
n]vCvmt
[3=Y 9P:
//启动子线程 ,l!>+@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IJ+}
for(int i=0;i<nStartPos.length;i++) 9Znc|<
{ b`%u}^B {
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vy2<'V*y}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \6GNKeN
nStartPos,nEndPos,i); V%[t'uh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fqbWD)L]
fileSplitterFetch.start(); 0X99D2c
} jSBz),.XU}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6t!=k6`1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 512p\x@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]LsT
nEndPos = " + nFileLength); :)Es]wA#HZ
// fileSplitterFetch[nPos.length-1].start(); WyV,(~y
6|Dtx5 "r
[ {"x{;
//等待子线程结束 R%LFFMVn
//int count = 0; <9H3d7%
//是否结束while循环 JkR%o #>5
boolean breakWhile = false; noaR3)
S7j(4@
`[E-V
while(!bStop) {pi_yr3
{ f }r \
write_nPos(); 2ia&c@P-
Utility.sleep(500); Q2oo\
breakWhile = true; 8MW-JZ
5o{U$
dVq9'{[3
for(int i=0;i<nStartPos.length;i++) Jo qhmn$j
{ )Dms9:
if(!fileSplitterFetch.bDownOver) KiMlbF.~V
{ *eD[[HbKX
breakWhile = false; l %zbx"%x
break; iiuT:r
} x]Nx,tt
} 2OI 0B\
if(breakWhile) 0 -M i q
break; Uun0FCA>
(MqQ3ys
KBi(Ns#+
//count++; %q r,Ssa/
//if(count>4) N:'GNMu
// siteStop(); AzzHpfv,
} M-;MwLx
Xa-TNnws?
u1kCvi#N
System.err.println("文件下载结束！"); *Q2 oc:6
} _UP 9b@Z"
catch(Exception e){e.printStackTrace ();} /Xc9}~t6
} 1fJ~Wp @1
a{^2c!
[Ous|a[)o
//获得文件长度 [[w-~hHH-
public long getFileSize() Ymnh%wS
{ Qru&lAYc<
int nFileLength = -1; 3XUVUd~
try{ X?ZLmP7|
URL url = new URL(siteInfoBean.getSSiteURL()); US's`Ehx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *>2FcoN;
httpConnection.setRequestProperty("User-Agent","NetFox"); {]|<|vc;GI
V]]!0ugvk(
tpzh
int responseCode=httpConnection.getResponseCode(); ~tL:r=
if(responseCode>=400) B<myt79F_[
{ JSq3)o9?/
processErrorCode(responseCode); LO%e1y
return -2; //-2 represent access is error E>#@ H
} S,|ZCl>+
J7dHD(R8
]p4?nT@]
String sHeader; S+Ia2O)BA
^v5]Aq~X
Pdh`Gu1:3
for(int i=1;;i++) &&jQ4@m}j
{ @b2?BSdUp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /EHO(d!<
//Utility.log(in.readLine()); T.QJ#vKO0
sHeader=httpConnection.getHeaderFieldKey(i); "Ar|i8^G3
if(sHeader!=null) S^i8VYK,C5
{ K5<2jl3S
if(sHeader.equals("Content-Length")) it>Bf;
{ B`nI]_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qxyY2&
break; 3z#>1HD$
} e&A3=a~\s
} -=lL{oB1
else Pec40g:#F
break; 3ohHBo
} $t6t 6<M)
} 3,!IV"_
catch(IOException e){e.printStackTrace ();} 247vU1
catch(Exception e){e.printStackTrace ();} `6YN/"unfp
D5Jg(-
V2;Nv\J\
Utility.log(nFileLength); Az(,Q$"|5
ncVt(!c,e
2A*,9S|Y
return nFileLength; 4QPHT#eqX
} >#;_Ebl@
2w~Vb0
8"LM:0x
//保存下载信息（文件指针位置） [EVyCIcY,h
private void write_nPos() C>-}BeY!
{ S,,Wb&A$
try{ iB~dO @
output = new DataOutputStream(new FileOutputStream(tmpFile)); S<*1b 6%D
output.writeInt(nStartPos.length); +?QHSIQo
for(int i=0;i<nStartPos.length;i++) VgY6M_V
{ W<O/LHKHdn
// output.writeLong(nPos); c/F!cW{z^
output.writeLong(fileSplitterFetch.nStartPos); Q?>*h xzoP
output.writeLong(fileSplitterFetch.nEndPos); |Ul4n@+2
} 8t7r^[T
output.close(); G7GKO
} KB^GC5L>
catch(IOException e){e.printStackTrace ();} 9qzHy}A
catch(Exception e){e.printStackTrace ();} A;^{%S
} "WPWMQ+
YOfYa
6/'X$}X
//读取保存的下载信息（文件指针位置） t82*rCIB{
private void read_nPos() 2>J;P C[;
{ XfEp_.~JM
try{ )\W}&9 >
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6Y.k<oem
int nCount = input.readInt(); LF(S"Of
nStartPos = new long[nCount]; /7a3*a
nEndPos = new long[nCount]; 3c:fYE
for(int i=0;i<nStartPos.length;i++) 1b7?6CqV
{ P=E10
nStartPos = input.readLong(); f*m^x7
nEndPos = input.readLong(); I;<__
} r'|ei,
input.close(); ,>kXn1 ,
} ]g%HU%R-m
catch(IOException e){e.printStackTrace ();} C.}ho.} r
catch(Exception e){e.printStackTrace ();} *Hv d
} Pc+,iK>
^|!\IzDp
e-xT.RnQ
private void processErrorCode(int nErrorCode) W3X;c*j
{ ePSD#kY5
System.err.println("Error Code : " + nErrorCode); Y'}c$*OkI
} :4\_upRE
]N1,"W}
hbx+*KM
//停止文件下载 B>"-8#B[4
public void siteStop() 11!4#z6w
{ a6d|Ps.\!
bStop = true; mkgL/h*
for(int i=0;i<nStartPos.length;i++) -l"8L;`
fileSplitterFetch.splitterStop(); xi.QHKBZaH
2@&"*1(Xu
t?;=\%^<
} sI#h&V,9
} IpKI6[2{`f
//负责部分文件的抓取 p@?(m/m$
**FileSplitterFetch.java 5a&gdqg]
*/ # M Y4Mr
package NetFox; O=u.J8S2
l`:-B'WM
An BM*5G
import java.io.*; F=UW[zy/[
import java.net.*; COH.`Tv{*
09iD| $~
,M\/[_:
public class FileSplitterFetch extends Thread { dVJ9cJ9^
bvJ*REPL?
n*~#]%4
String sURL; //File URL v=IcVHuf
long nStartPos; //File Snippet Start Position '?$<k@mJW
long nEndPos; //File Snippet End Position zHW&i~
int nThreadID; //Thread's ID wA87|YK8*
boolean bDownOver = false; //Downing is over 'E\qqE[;
boolean bStop = false; //Stop identical tK\$LZ
FileAccessI fileAccessI = null; //File Access interface nxuR^6Ai
x ;]em9b
E_xk8X~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %!L*ec%,
{ Ds8x9v)^
this.sURL = sURL; %VrMlG4hx
this.nStartPos = nStart; UwDoueXs
this.nEndPos = nEnd; PJh97%7
nThreadID = id; '?E@H.""
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A.!3{pAb
} ?Xp+5{
NL"w#kTc()
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public void run() ggHl{cl)
{ !U1V('
while(nStartPos < nEndPos && !bStop) J=#9eW
{ 8ePzUc\#
;s-fYS6(>{
!Ome;gS)
try{ \JF 2'm\M
URL url = new URL(sURL); b]WvKdq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r+MqjdXG
httpConnection.setRequestProperty("User-Agent","NetFox"); kChCo0Q>1
String sProperty = "bytes="+nStartPos+"-"; _<)HFg6
httpConnection.setRequestProperty("RANGE",sProperty); =?hbi]
Utility.log(sProperty); H|cxy?iJ
G?+]BIiL
ZZ].h2=K
InputStream input = httpConnection.getInputStream(); G;AV~1i:~
//logResponseHead(httpConnection); 6 c-9[-Px
*x.gPG
:XO7#P
byte[] b = new byte[1024]; c{/KkmI
int nRead; Nw3IDy~T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i32S(3se
{ rT{2
nStartPos += fileAccessI.write(b,0,nRead); N)YoWA>#bF
//if(nThreadID == 1) :-b-)*TC;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^cojETOv
} 7"{CBbT
S`[r]msw
2AjP2
Utility.log("Thread " + nThreadID + " is over!"); x=44ITe1n[
bDownOver = true; PE+{<[n
//nPos = fileAccessI.write (b,0,nRead); `6G:<wX
} l{3ZN"`I
catch(Exception e){e.printStackTrace ();} p/jAr+XM
} fR lJ`\ t
} bj+foNvu\
*18J$
)B Xl|V,
//打印回应的头信息 5R#:ALwX:
public void logResponseHead(HttpURLConnection con) Now2ad&
{ I]N!cEr;@-
for(int i=1;;i++) dcN4N5r
{ I,?!NzB
String header=con.getHeaderFieldKey(i); 7FP @ vng
if(header!=null) O}[){*GG=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _jk+$`[9PL
Utility.log(header+" : "+con.getHeaderField(header)); ~*G}+Ur$2
else z&A#d
break; KRj3??b
} tqOx8%
} ?h ym~,
+D#.u^
koT: r
public void splitterStop() ;0E[ ; L!
{ 9h^TOZK)
bStop = true; g);.".@"
} $s5D/60nO
<D(|}5qR
~fly6j|u
} ltmD=-]G_
q62U+o9G
9B1bq#
/* [AAIBb+U
**FileAccess.java @S Quc
*//文件访问(定位，写) Y/34~lhyl
package NetFox; }719_DF
import java.io.*; R&1xZFj
2rX}A3%9^^
c}#(,<8X
public class FileAccessI implements Serializable{ qk\LfRbj
Z+! 96LR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -<gQ>`(0
RandomAccessFile oSavedFile; x!9bvQT
long nPos; ut9R]01:
ZvW&%*k=
l)91v"vJ
public FileAccessI() throws IOException VV=6v;u`
{ ]hA]o7k
this("",0); LfG$?<}hR
} Kl+4A}Uo
I$Fr8R$
K|{&SU_m
public FileAccessI(String sName,long nPos) throws IOException q|R$A8)L.
{ 4S,/Z{ J.
oSavedFile = new RandomAccessFile(sName,"rw"); D$bJs O
this.nPos = nPos; <e'l"3+9(
oSavedFile.seek(nPos); vTYgWR,h
} }{ "RgT-qG
M9sB2Ips<
K/XUF#^B]
public synchronized int write(byte[] b,int nStart,int nLen) 3x~AaC.j
{ 15`,kJSK
int n = -1; }zV#?;}
try{ VufG7%S{
oSavedFile.write(b,nStart,nLen); .[X"+i\
n = nLen; 3O'X;s2\d
} U7Pn $l2!
catch(IOException e) 8*yky
{ tsqWnz=)
e.printStackTrace (); 5[>N[}Ck>
} dZjh@yGP.
,zrShliU
KXga{]G:
return n; aOo;~u2-=
} ?VT ]bxb
Jl^THoEL
JB\BP$ap
} &5;y&dh
FuZLE%gP
gT4H? #UB
/* =)y=39&;/
**SiteInfoBean.java lIL{*q(
*/ ,V:RE y
package NetFox; TGQDt|+Z
$^"_Fox]A\
dq$CCOC^F
public class SiteInfoBean { 'QEQyJ0EB
^,;8ra*h
h\$juIQa
private String sSiteURL; //Site's URL r$.v"Wh)
private String sFilePath; //Saved File's Path f@= lK?Pfh
private String sFileName; //Saved File's Name .TWX,#
private int nSplitter; //Count of Splited Downloading File Y=N; Bj
<E&"]
) _O6_
public SiteInfoBean() T@H2[ 7[;
{//nSplitter的缺省值为5 ;Cqjg.wkB
//default value of nSplitter is 5 N?;5%pG <
this("","","",5); W&(98}oT
} rSfvHO:R
O1K~]Nt
#>byP?)n
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {^n\ r^5
{ 0NWtu]9QC
sSiteURL= sURL; cxQ8/0^
sFilePath = sPath; p~THliwd
sFileName = sName; -#?p16qz5
this.nSplitter = nSpiltter; (Eoji7U
g?caE)
j;b<oQH
} 1z[GYRSt
y:+s*x6Vg
%?WmWs0
public String getSSiteURL() -'!%\E;5
{ U1^R+ *yp
return sSiteURL; `L=$,7`
} S4Vv _k-&
sZhl.[&zo
l6Q75i)eF
public void setSSiteURL(String value) #GHLF
{ ]xIfgSq
sSiteURL = value; [#R<Z+c
} %L9A6%gr
(^Kcyag4
zl!`*{T{
public String getSFilePath() U'acVcD
{ 1$Pn;jg:
return sFilePath; h8!;RN[
} KGm"-W
){oVVLs
W}5H'D
public void setSFilePath(String value) _(8HK
{ h7S&tW GU
sFilePath = value; (g@e=m7Q
} zz4A,XrD
@pD']=d}t
Bu$GCSrX
public String getSFileName() :K6(`J3Y"^
{ o= %Fh
return sFileName; 9GZKT{*
} [af<FQ{
emV@kN.
9)qjW&`
public void setSFileName(String value) '?~k`zK
{ ?DC3BA\)
sFileName = value; N|ut^X+|\
} 1+^L,-k!
Xx0}KJq~"
_;BN;].
public int getNSplitter() Ek,s6B)'d
{ f9FsZD
return nSplitter; 2Ax HhD.
} Tdr^~dcQ
[-sE:O`yt
kE".v|@
public void setNSplitter(int nCount) @:. 6'ji,`
{ gi7As$+E
nSplitter = nCount; n8M/Y}mH
} F%6`D
} imtW[y+4
|^ml|cb
zSYWNmj&
/* m GWT</=[$
**Utility.java "l&sDh%Lk<
*/ &0 VM <
package NetFox; {=,?]Z+
ud`.}H~aB
%Ya-;&;`
public class Utility { t$=0 C
Nky%v+r
OX?9 3AlG
public Utility() >29eu^~nh
{ 5CkM0G`
P$)9osr
x c-=;|s
} 56o?=|
dxkXt k
//线程睡眠 @Ey(0BxNu
public static void sleep(int nSecond) I@ch 5vl4
{ (*%+!PS
try{ u+zq:2)H6
Thread.sleep(nSecond); HPT9B?^
} h.QKbbDj
catch(Exception e) ,7pO-:*g
{ 1GW=QbO 6
e.printStackTrace (); }@OykN
} mV;Egm{A\
} 4kA/W0 VG
h"YIAQ',
//日志 d*1@lmV*
public static void log(String sMsg) ZBJYpeGe
{ b=QO^
System.err.println(sMsg); odquAqn
} 0}Xkj)R,
COj50t/
"0g1'az}
public static void log(int sMsg) @)m+O#a
{ F5J=+Q%8[&
System.err.println(sMsg); ;G~0 VM2|
} 9h$-:y3
} ;P _`4w3
SM:{o&S`
D;<Qm,[
/* _qmBPUx
**TestMethod.java +iwNM+K/gQ
*/ 2u6N';jgZ
package NetFox; DnaG$a<
)j@k[}R#g
}{Lf 4|8
public class TestMethod { -b(:kAwStk
[/*854
"aP>}5<h
public TestMethod() E+"INX7
{ ///xx/weblogic60b2_win.exe @}x)>tqD
try{ bsPwTp^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1(!QutEb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [ WZ<d^L
SiteFileFetch fileFetch = new SiteFileFetch(bean); ix]3t^
fileFetch.start(); X?Omk, '
} '8k\a{t_z
catch(Exception e){e.printStackTrace ();} (1(3:)@S6
Os8]iNvW\
8R:H{)o~s}
} r#]gAG4t\
uHQJ&
42Vy#t/HC
public static void main(String[] args) *s?&)][
{ &6MGPh7T
new TestMethod(); N"T~U\R
} _:M6~XHo
} pLBp[GQ
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