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)); #e0+;kBh
} 4v?S`w:6
for(int i=0;i<nEndPos.length-1;i++) O0I/^
{ `150$*K&B
nEndPos = nStartPos[i+1]; }z*p2)v`
} \4&g5vE
nEndPos[nEndPos.length-1] = nFileLength; 7)]G"m{
} 6$Dbeb
} }$UFc1He\J
l{3utQH-=z
BxG;vS3>*e
//启动子线程 /[-hJ=<Yb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >ylVES/V
for(int i=0;i<nStartPos.length;i++) @GV^B'}*
{ YJ0[BcZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ["7}u^z@<+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n#R!`*[
nStartPos,nEndPos,i); {F4:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =osj}(
fileSplitterFetch.start(); 7D^A:f
} *Zvw&y*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iOyYf!yg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yqU++;6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?b0\[
nEndPos = " + nFileLength); ;Cy@TzO/|
// fileSplitterFetch[nPos.length-1].start(); wVVe L$28
L9.#/%I\
Zry>s0
//等待子线程结束 o?3R HP47
//int count = 0; (!b: gG
//是否结束while循环 s6$3[9Vh&9
boolean breakWhile = false; gM*s/,;O"
p%s D>1k
i~;8'>:|,M
while(!bStop) S;NXOsSu
{ |);>wV"
write_nPos(); >&VL2xLy
Utility.sleep(500); 1gE`_%?K
breakWhile = true; VtO+=mZV
1 W0;YcT]
,uv$oP-
for(int i=0;i<nStartPos.length;i++) aPC!M4#
{ =%3nKSg
if(!fileSplitterFetch.bDownOver) b>i=",i\
{ #^9;<@M
breakWhile = false; 8syo_sC |
break; coWBKWF
} Y[!a82MTzn
} ^6+x0[13
if(breakWhile) zCHr
break; B /W$RcV
;i9CQ0e?
#-;BU{3*
//count++; 1 XG-O
//if(count>4) `9ox?|iJ
// siteStop(); L,6Y=?
} OLrD4 e
FT~^$)8=
L3AwL)I
System.err.println("文件下载结束！"); k3 l
} />C~a]}
catch(Exception e){e.printStackTrace ();} 9QMn%8=j
} X2cR+Ha0
qN@a<row&~
j;)6uia*A
//获得文件长度 yr>bL"!CA
public long getFileSize() Aq!['G
{ $1+K}tP
int nFileLength = -1; *K|aK p}
try{ ?^~"x.<nr
URL url = new URL(siteInfoBean.getSSiteURL()); >K :"[?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %K"%Qm=Tl
httpConnection.setRequestProperty("User-Agent","NetFox"); CeTr%j
G+uiZ(p>
ImY.HB^&
int responseCode=httpConnection.getResponseCode(); h '[vB^
if(responseCode>=400) P0xLx
{ (L$~zw5gr
processErrorCode(responseCode); Nz*sD^SJa
return -2; //-2 represent access is error au|^V^m
} (:QQ7xc{}
zXZ'nJ5OGG
VA'X!(Cv
String sHeader; (0W}e(D8
ht)nx,e=
%i8>w:@NW
for(int i=1;;i++) /w M
{ 6 ]Oxx{|}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |xZcT4
//Utility.log(in.readLine()); iIaT1i4t.
sHeader=httpConnection.getHeaderFieldKey(i); hw$c@:pW;
if(sHeader!=null) *ldMr{s<R
{ vQ"s
if(sHeader.equals("Content-Length")) 5xDN&su
{ HhmVV"g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cmhN(==
break; 3]<re{)J9O
} 45sxF?GSwL
} [Cj}nld
else *3O>J"
break; S tnv>
} 6@q[tN7_^
} &3Z. #*
catch(IOException e){e.printStackTrace ();} +'/}[1q1/T
catch(Exception e){e.printStackTrace ();} x XM!E 8
PCPf*G>
]A72)1
Utility.log(nFileLength); oL Vtu5
@f{_=~+
Y#&0x_Z
return nFileLength; c5E#QV0&v~
} 5!F\h'E
iv:/g|MBI&
s!ZW'`4!z
//保存下载信息（文件指针位置） F`0c?)
private void write_nPos() <*"pra{3
{ #)0Tt>d6
try{ D!}K)T1~R
output = new DataOutputStream(new FileOutputStream(tmpFile)); w,Zx5bBg%
output.writeInt(nStartPos.length); .S!>9X,
for(int i=0;i<nStartPos.length;i++) XDkS ^9
{ "f|(@a
// output.writeLong(nPos); Z-SwJtWk
output.writeLong(fileSplitterFetch.nStartPos); AB"1(PbG
output.writeLong(fileSplitterFetch.nEndPos); AL]h|)6QpC
} oY%"2PW1B
output.close(); a,~D+s;^
} R+E_#lP_$
catch(IOException e){e.printStackTrace ();} +Cf0Y2*@hM
catch(Exception e){e.printStackTrace ();} iog # ,
} H5Ux.]y
1a&/Zlr
Wk`bb!P_
//读取保存的下载信息（文件指针位置） IAP/G5'Q
private void read_nPos() cXS;z.M\_
{ g={]Mzh
try{ =!(*5\IM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mN\%fJ7
int nCount = input.readInt(); #9D/jYK1X
nStartPos = new long[nCount]; SbS$(Gt#Bv
nEndPos = new long[nCount]; =Y&9 qt
for(int i=0;i<nStartPos.length;i++) 7-".!M
{ *%X6F~h(u
nStartPos = input.readLong(); <E>7>ZL
nEndPos = input.readLong(); "H>r-cyh
} X-kXg)!Bg
input.close(); -(\1r2 Y
} x0\e<x9s
catch(IOException e){e.printStackTrace ();} g.I(WJX0
catch(Exception e){e.printStackTrace ();} @s%X
} ]<27Sw&yaG
}_{y|NW
=oE_.ux\
private void processErrorCode(int nErrorCode) %cH8;5U40
{ >vWEUE[
System.err.println("Error Code : " + nErrorCode); {I0w`xe
} R=-+YBw7/
6exI_3A4jh
{TyCj?3B
//停止文件下载 vv+TKO
public void siteStop() =X%!YZk p
{ CifA,[l34
bStop = true; \U/v;Ijf
for(int i=0;i<nStartPos.length;i++) _*s~`jn{H
fileSplitterFetch.splitterStop(); 1ZT^)/G
C,o:
]SFWt/<
} ,{k<JA{
} w#*/y?"D
//负责部分文件的抓取 m_a^RB(
**FileSplitterFetch.java \UQ9MX _
*/ bqSMDK
package NetFox; jm+ V$YBP
pe|X@o
d9O:,DKf
import java.io.*; ^6Yd}
import java.net.*; wHx}U M"
/K7Bae5h
.>}BNy
public class FileSplitterFetch extends Thread { *oCxof9JA
Zr=ib
BU`ckK\(
String sURL; //File URL 5J ySFG3
long nStartPos; //File Snippet Start Position _=pWG^a
long nEndPos; //File Snippet End Position Nj+a2[
int nThreadID; //Thread's ID `|nH1sHFq
boolean bDownOver = false; //Downing is over TN5>"??"
boolean bStop = false; //Stop identical z<!O!wX_aI
FileAccessI fileAccessI = null; //File Access interface Tr~sieL
$!f!,fw+
80C(H!^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cS4DN
{ u^t$cLIZ
this.sURL = sURL; 7'z(~3D
this.nStartPos = nStart; p!_[qs
this.nEndPos = nEnd; Nb0Ik/:<
nThreadID = id; q]CeD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Zae.MO^C!
} C0QM#"[
zVw:7-
O5zE {#
public void run() RND9D\7
{ e?b)p5g
while(nStartPos < nEndPos && !bStop) e4DMO*6
{ t8P PE
j C)-`_
)n>+m|IqY(
try{ /&r|ec5
URL url = new URL(sURL); 4ZwKpQ6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nBkh:5E5%
httpConnection.setRequestProperty("User-Agent","NetFox"); Zyu/|Og
String sProperty = "bytes="+nStartPos+"-"; -\4zwIH
httpConnection.setRequestProperty("RANGE",sProperty); iPvuz7j=h
Utility.log(sProperty); 3@_Elu
E$A3|rjnoN
ygzxCn|#
InputStream input = httpConnection.getInputStream(); gv|"OlB
//logResponseHead(httpConnection); <F(><Xw,-4
)"|||\Iv
Wpr ,jN8b
byte[] b = new byte[1024]; tlQC6Fb#
int nRead; -R b{^/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wP<07t[-g
{ WF[bO7:
nStartPos += fileAccessI.write(b,0,nRead); ^nNitF
//if(nThreadID == 1) * ?]~ #
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XogVpkA
} d|lpec
Hr^3`@}#1
yCP4r6X0
Utility.log("Thread " + nThreadID + " is over!"); F9a^ED0l\
bDownOver = true; u5+|Su
//nPos = fileAccessI.write (b,0,nRead); 69OF_/23
} p*20-!{A
catch(Exception e){e.printStackTrace ();} 9t$]X>}
} -1u9t4+`
} Gh\q^?}
}ptq )p
iM]o"qOQm
//打印回应的头信息 _>yoX
public void logResponseHead(HttpURLConnection con) 2VGg 6%
{ NxA)@9Q
for(int i=1;;i++) ]uQqn]+I!
{ yN6>VD{F
String header=con.getHeaderFieldKey(i); yZkyC'/
if(header!=null) B*3Y!!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /.z;\=;[n!
Utility.log(header+" : "+con.getHeaderField(header)); rsXq- Pq*
else ~1L:_Sg*
break; )B$;Vs]@i
} ,|kDsR!
} 4\M.6])_
.2) =vf'd
Sa1l=^
public void splitterStop() jMNU ?m:
{ \S~Vx!9w
bStop = true; kwpK1R4zs
} YXo|~p;=Y
Qnd5X`jF#
*%/~mSx
} umi5Wb<
QPtGdd
kOo~%kcQ'
/* Z|"p*5O,
**FileAccess.java 7R!5,Js+
*//文件访问(定位，写) L|@y&di
package NetFox; \*f;Xaa
import java.io.*; Vv1|51B
R:Q0=PzDi#
Z_1U9+,
public class FileAccessI implements Serializable{ 91>fqe
_BdE< !r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VA*y|Q6
RandomAccessFile oSavedFile; `K~AhlJUQ
long nPos; YQJ==C1
)WT>@
JM1R ;i6
public FileAccessI() throws IOException X3'H `/
{ r}[7x]sP
this("",0); <S?ddp2
} J]f3CU,<N
tyaA\F57
iY"l}.7)
public FileAccessI(String sName,long nPos) throws IOException ?v>ET2wD
{ m3Il3ZY.
oSavedFile = new RandomAccessFile(sName,"rw"); ?T+q/lt4
this.nPos = nPos; 4jD2FFG- G
oSavedFile.seek(nPos); -'~LjA(
} C4TE-OM8
(Jz;W<E
#9K-7je;j
public synchronized int write(byte[] b,int nStart,int nLen) NaX
{ 23~Sjr
int n = -1; @v}/zS
try{ )iFJz/n>
oSavedFile.write(b,nStart,nLen); r@ZJ{4\Q
n = nLen; `ZC<W]WYX/
} yX~v-N!X
catch(IOException e) x?&$ci
{ \7CGUB>L
e.printStackTrace (); bw\@W{a%q
} c y8;@[#9
;G%R<Z
Ja9e^`i;
return n; 6?w0
} `r?7oxN
BCA&mi3q
IIbYfPiO
} e=.]F*:J
=Q\r?(Iy
8YbE`32
/* cFJY^A
**SiteInfoBean.java MdW]MW{
*/ b9!FC$^J
package NetFox; P'_H/r/#
N0r16# -g
@Z12CrJ
public class SiteInfoBean { !jTcsN%
fZoHf\B]{
>Z5gSs0
private String sSiteURL; //Site's URL %\:[ o
private String sFilePath; //Saved File's Path _ jsK}- \
private String sFileName; //Saved File's Name >G%o,9i
private int nSplitter; //Count of Splited Downloading File K57&yVX
`G}TG(
-X"p:=;j
public SiteInfoBean() Hg=";,J
{//nSplitter的缺省值为5 va0{>Dc+
//default value of nSplitter is 5 r8xv#r1
this("","","",5); 5;YMqUkw
} ax<?GjpM
R21b!Pd\
C)`Fv=]R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c_4[e5z
{ N u<_}
sSiteURL= sURL; `)_dS&_\
sFilePath = sPath; @fl-3q
sFileName = sName; # mV{#B=
this.nSplitter = nSpiltter; .N ,3od@
1ng!G 7g
N/MUwx;P
} Hl{S]]z
;wz^gdh;
zem8G2#c
public String getSSiteURL() ~f$|HP}
{ |#]@Z)xa
return sSiteURL; I|^;B8[
} 7$CBx/X50)
.y!<t}
[OC5l>
public void setSSiteURL(String value) n>BkTaI
{ {xXsBh Y
sSiteURL = value; PHZ0P7
} _V7s#_p
pKpUXfQu
,$s8GAmq
public String getSFilePath() VY |_dk
{ `d5%.N
return sFilePath; bk;?9%TW
} "_-Po^u=r
ywGd>@
\LR~r%(rM
public void setSFilePath(String value) Oo5w?+t
{ Yc_8r+;(
sFilePath = value; < $J>9k
} 6dabU*
[q?<Qe
kMi/>gpQ
public String getSFileName() 1OCeN%4]Qk
{ IzikDc10
return sFileName; k/#&qC>]
} gQWa24
6#7Lm) g8
X[]m _@v
public void setSFileName(String value) xS4w5i2
{ EofymAi%
sFileName = value; ORe(]I`Z
} Ugu[|,
{o_X`rgrL
$WyD^|~SF
public int getNSplitter() iU$] {c2;A
{ b6nsg|&#
return nSplitter; ] o*#t
} >`Y.+4mE
~$Tkn_w#
ehzM)uK
public void setNSplitter(int nCount) *"?l]d
{ Tl(^
nSplitter = nCount; Xe6w|
} sqEI4~514
} ciBP7>'::
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k;K)xb[w|
/* ^o^H3m
**Utility.java 6G1@smP
*/ H$=e -L`@
package NetFox; 7C,&*Ax,9
.{ocV#{s
aoMqSwF=
public class Utility { tNO-e|~'
K-bD<X
ah+~y,Gl
public Utility() 5b*M*e&=C
{ 15%w 8u
mw_~*Nc'9
YLqGRE`W
} {IxA)v-`
l1T m`7}
//线程睡眠 ozmrw\_}[
public static void sleep(int nSecond) ?u{~>
{ QKyo`g7
try{ Rn}l6kbM
Thread.sleep(nSecond); (}{G`N>.{
} cc,^6[OH@
catch(Exception e) KC/=TSSXd.
{ {K+icTL3
e.printStackTrace (); :}5j##N
} .:@Ykdm4I
} JSkLEa~<
dCE0$3'5
//日志 DnC{YK
public static void log(String sMsg) #bUXgn>
{ 2;zb\d
System.err.println(sMsg); .n#@$ nGZ
} &|Bc7+/P
tX5"UQA
fmQ_P.c
public static void log(int sMsg) /M|262%
{ tXoWwQD;Y
System.err.println(sMsg); /j4P9y^]=
} u$>4F|=T
} q"%_tS
qs1 ?IYD
(pY 7J
/* N/Z2hn/m
**TestMethod.java !ipR$ dM
*/ ]Y%Vio
package NetFox; W?qmp|YD
2/?`J
43|XSyS
public class TestMethod { +aJ>rR
,VCyG:dw
v9:9E|,U+
public TestMethod() ur3(HL
{ ///xx/weblogic60b2_win.exe kddZZA3`
try{ x,rlrxI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); eIz<)-7:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,5|&A
SiteFileFetch fileFetch = new SiteFileFetch(bean); G`n_YH084
fileFetch.start(); Q?nN!eT
} ]Bcp;D
catch(Exception e){e.printStackTrace ();} {l>yi
v*;-yG&
H7d/X
} +_; l|uhT;
Ont%eC\
nSW=LjrO~<
public static void main(String[] args) 7[> 6i
{ y`F3Hr c
new TestMethod(); m;'6MHx;
} ]~aF2LJ_q
} )+[ gd/<C.
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