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)); +{")E)
} <fC@KY>#
for(int i=0;i<nEndPos.length-1;i++) S' (cqO}=F
{ @)W(q5)}9"
nEndPos = nStartPos[i+1]; .pS&0gBo\
} PcHSm/d0e
nEndPos[nEndPos.length-1] = nFileLength; ~7lTqY\
} yqC Q24
} e-CNQnO~
X$7Oo^1;
h&=O-5
//启动子线程 GSMk\9SI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pl rkgS0J
for(int i=0;i<nStartPos.length;i++) &v5G92
{ g.B%#bfg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^CZCZ,v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }}^,7npU
nStartPos,nEndPos,i); ID67?:%r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jv_.itc
fileSplitterFetch.start(); B ~fSMB6h
} Vq3gceo'0A
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !_CX2|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YCa@R!M*O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qP~WEcH`[
nEndPos = " + nFileLength); Ds%9cp*6
// fileSplitterFetch[nPos.length-1].start(); [[:UhrH-
?PBa'g
E,{GU
//等待子线程结束 L'zE<3O'3
//int count = 0; aq3~!T;W
//是否结束while循环 ,Bisu:v6FW
boolean breakWhile = false; c |>=S)|
:P3{Nxa
IByf_E;r
while(!bStop) ?Bo?JMV
{ D`6iDit
write_nPos(); ')B =|T)
Utility.sleep(500); J,f/fPaf7
breakWhile = true; 6cM<>&e
rh@r\H@j
f|OI`
for(int i=0;i<nStartPos.length;i++) 8wr8:(Y$
{ S_J,[#&
if(!fileSplitterFetch.bDownOver) *HR+a#o
{ et=7}K]l
breakWhile = false; geksjVwPH
break; R{HV]o|qk
} sf(iE(o
} O|QUNr9
if(breakWhile) KU-'+k2s;p
break; j~bAbOX12
]*qU+&
-"=)z/S
//count++; #ZJMlJ:q`"
//if(count>4) OTj,O77k
// siteStop(); Hou*lCA
} bNGCOj
Z7fg 25
T-'~?[v
System.err.println("文件下载结束！"); 'BY-OA#xJ
} w/W7N
catch(Exception e){e.printStackTrace ();} u:@U $:sZ
} k;k}qq`d
=!BobC- [b
[$pmPr2
//获得文件长度 jNA1O68N
public long getFileSize() )P?IqSEA%
{ B:< ]Hl$
int nFileLength = -1; .h4\{|
try{ ?s?$d&h
URL url = new URL(siteInfoBean.getSSiteURL()); 5u r)uz]w8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zvY+R\,in
httpConnection.setRequestProperty("User-Agent","NetFox"); 3uV4/%U
!4WEk
7\ypW$Ot
int responseCode=httpConnection.getResponseCode(); KB!5u9
if(responseCode>=400) ib$nc2BPb
{ KVkMU?6
processErrorCode(responseCode); & ze>X
return -2; //-2 represent access is error =bLY /
} d--'Rn5
TJ(K3/)Z
9XLFHV("
String sHeader; WA6!+Gy
KL [ek
c3)C{9T](
for(int i=1;;i++) yHeEobvb
{ 4nqoZk^R
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w8Vw1wW
//Utility.log(in.readLine()); bc I']WgB-
sHeader=httpConnection.getHeaderFieldKey(i); HpVjee
if(sHeader!=null) geM6G$V&
{ fvEAIs
if(sHeader.equals("Content-Length")) nwA8ALhE
{ hePPxKQ-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OtTBErQNF
break; 5GQLd
} >9H@|[C
} +9XQ[57
else :7g=b%;
break; T6#CK
} WC,+Cn e
} ?wb+L
catch(IOException e){e.printStackTrace ();} X^@I].
catch(Exception e){e.printStackTrace ();} 17|np2~
pI.+"Hz
=IU*}>#
Utility.log(nFileLength); \.uc06
wQ+8\ s=
LD>\#q8a*
return nFileLength; *Dmx&F=3,5
} 1LnyWZ
dRi5hC$
B@y(.
//保存下载信息（文件指针位置） <7_KeOLJ
private void write_nPos() ::5E8919
{ !#2=\LUC
try{ ?GA&f2]a
output = new DataOutputStream(new FileOutputStream(tmpFile)); ORN6vX(1
output.writeInt(nStartPos.length); "LhvzM-<8
for(int i=0;i<nStartPos.length;i++) "O[j!fG8,
{ N587(wZ
// output.writeLong(nPos); o>Er_r
output.writeLong(fileSplitterFetch.nStartPos); (X[CsaXt
output.writeLong(fileSplitterFetch.nEndPos); N K]B?
} ? "/ fPV-
output.close(); Iu@y(wyg
} R\|lt)h
catch(IOException e){e.printStackTrace ();} n5-)/R[z
catch(Exception e){e.printStackTrace ();} laKuOx}
} !7bw5H
Lw1EWN6}_&
zSEs?
//读取保存的下载信息（文件指针位置） )D&M2CUw"f
private void read_nPos() cO2& VC
{ !4"^`ors$
try{ U69u'G:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fBn"kr;
int nCount = input.readInt(); 4Y> Yi*n
nStartPos = new long[nCount]; (-77[+2
nEndPos = new long[nCount]; Ny- [9S-<
for(int i=0;i<nStartPos.length;i++) YevyN\,}V!
{ M:KbD|
nStartPos = input.readLong(); G!N{NCq
nEndPos = input.readLong(); l_'[27
} N==ZtKj F
input.close(); (>4aibA'P
} :~Q!SL N
catch(IOException e){e.printStackTrace ();} }R[#?ty;]
catch(Exception e){e.printStackTrace ();} $?G"GQ!.
} J5p"7bc
$rF=_D6
kum#^^4G|
private void processErrorCode(int nErrorCode) 7hW+T7u?
{ ._w8J"E5
System.err.println("Error Code : " + nErrorCode); :<Y}l-x
} [D-Q'"'A
9^"b*&>P
g"s$}5{8:
//停止文件下载 ,#FLM`
public void siteStop() 9E2j!
{ acP+3u?r
bStop = true; Rlnbdb;!k
for(int i=0;i<nStartPos.length;i++) 1OLqL
fileSplitterFetch.splitterStop(); ?bZovRx
\!vN
gWABY%!}
} v~3B:k:?l
} 3f" %G\
//负责部分文件的抓取 v2r&('pV
**FileSplitterFetch.java UJfT!==U
*/ >d"3<S ;b
package NetFox; n\Fp[9+Z\
&AVpLf:?
{t"+ 3zy'
import java.io.*; Oa;X+
import java.net.*; EN{]Qb06A
!Cgx.
YjF|XPv+ l
public class FileSplitterFetch extends Thread { CQ`=V2:"ON
LE5.b]tv2
sDr/k`>
String sURL; //File URL SG}V[Glk
long nStartPos; //File Snippet Start Position Gb[`R}^dq
long nEndPos; //File Snippet End Position ;6@r-r
int nThreadID; //Thread's ID Spo?i.#
boolean bDownOver = false; //Downing is over ~ ~uAc_
boolean bStop = false; //Stop identical 8l}1c=A}Vi
FileAccessI fileAccessI = null; //File Access interface 2!&&|Mh}
j'[m:/
^-FX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yR{x}DbG
{ b" xmqWa
this.sURL = sURL; CT0l!J~5m~
this.nStartPos = nStart; 7Dnp'*H
this.nEndPos = nEnd; l`kWz5[~
nThreadID = id; 5aad$f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .=m,hu~
} x!\ONF5$
oH0X<'
43?^7_l-
public void run() _&K
{ |KB0P@=a
while(nStartPos < nEndPos && !bStop) j!7`]
{ U\/5;Txy(
yC 77c=
UnVm1ZWZ
try{ .@ xF6UZ
URL url = new URL(sURL); +("7ZK?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0 a]/%y3V
httpConnection.setRequestProperty("User-Agent","NetFox"); ??TMSH
String sProperty = "bytes="+nStartPos+"-"; QL6C,#6
httpConnection.setRequestProperty("RANGE",sProperty); Kp+CH7I*
Utility.log(sProperty); Rqwzh@}
,q(&)L$S
bjAnaya
InputStream input = httpConnection.getInputStream(); ThPE 0V
//logResponseHead(httpConnection); 7+x? "4
]9}HEu;1M
tm7u^9]
byte[] b = new byte[1024]; sr@j$G#uW5
int nRead; r{L4]|(utY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) eh,~^x5
{ l5l>d62
nStartPos += fileAccessI.write(b,0,nRead); SIBoCs5
//if(nThreadID == 1) eEhr140
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yj4+5`|f
} #:T-hRu
pJN${
Kwc6mlw~M
Utility.log("Thread " + nThreadID + " is over!"); VqL.iZ-
bDownOver = true; +[SgO}sF
//nPos = fileAccessI.write (b,0,nRead); 2pdvWWh3l
} pP(XIC
catch(Exception e){e.printStackTrace ();} cyxuK*x<
} E}%hz*Q)(
} 5[j`6l
T~h5B(J;
AeAp0cbet
//打印回应的头信息 ;3_l@dP"
public void logResponseHead(HttpURLConnection con) .z13 =yv
{ 52upoU>}2
for(int i=1;;i++) [ sd;`xk
{ qj cp65^
String header=con.getHeaderFieldKey(i); ]%Zz \Q
if(header!=null) NEa>\K<\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p4VeRJk%
Utility.log(header+" : "+con.getHeaderField(header)); zhY+x<-
else hzk6rYg1
break; nQ|r"|g
} r\nx=
} ie-vqLc
zE;bBwy&
Be+0NXLVy
public void splitterStop() %e*@CbO$
{ <0S=,!
bStop = true; S*AERm
} Lg"C]
e.c3nKXZ q
KR7@[
} mo~*C
p}[zt#v
=_YG#yS
/* 0ZQ'_g|%
**FileAccess.java ccd8O{G.M
*//文件访问(定位，写) 1:Si,d,wh
package NetFox; 4Jx"A\5*G
import java.io.*; YJ(*wByM
d#2$!z#
yoAfc
public class FileAccessI implements Serializable{ &~CY]PN.
B c2p(z4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >vo=]cw
RandomAccessFile oSavedFile; q\\gpCgp
long nPos; vFEQ7qI
/ g 2b
IHRGw
public FileAccessI() throws IOException kA7mLrON
{ H(Eh c
this("",0); I@\OaUGr+
} BC'llD
OT&k.!=
Y2'cs~~$Ce
public FileAccessI(String sName,long nPos) throws IOException ]~Y<o
{ (rg;IXAq%
oSavedFile = new RandomAccessFile(sName,"rw"); KD^N)&k^Kp
this.nPos = nPos; ZoArQ(YFy
oSavedFile.seek(nPos); h;3cd0
} 3j3N!T9
Fv<`AU
r1fGJv1!o
public synchronized int write(byte[] b,int nStart,int nLen) B7]MGXC
{ P'Q+GRpSw
int n = -1; /r_~:3F
try{ H.UX,O@
oSavedFile.write(b,nStart,nLen); [V:\\$
n = nLen; 2k<;R':
} fA89|NTSUh
catch(IOException e) |r bWYl.b
{ <oz!H[!
e.printStackTrace (); zRPeNdX
} vB+ '
Zdn~`Q{
"1,pHR-+R
return n; 0T46sm r
} 'fPdpnJ<
r[K5w
MX+Z ?
} |\n_OS7
N<DGw?Rl
jbR0%X2
/* E\C9|1)
**SiteInfoBean.java K(q-?n`<
*/ *YlV-C<}W"
package NetFox; >$2V%};
"le>_Ze_>|
p0pWzwTG3
public class SiteInfoBean { ?mlNL/:
h>Hb`G<
-1J[n0O.
private String sSiteURL; //Site's URL +T8B:
private String sFilePath; //Saved File's Path uw2hMt (N
private String sFileName; //Saved File's Name D.mHIsX6\
private int nSplitter; //Count of Splited Downloading File /JT#^Y
a.z;t8
`UBYp p
public SiteInfoBean() gJM`[x`T
{//nSplitter的缺省值为5 Y/7 $1k
//default value of nSplitter is 5 H@l}WihW
this("","","",5); !fj(tPq
} ZI=v.wa
<ZB1Vi9}8
?@V[#.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FHV-BuH5
{ ^+g$iM[`f
sSiteURL= sURL; jRL<JZ1N
sFilePath = sPath; )&!&AlLn
sFileName = sName; :kGU,>BN
this.nSplitter = nSpiltter; KIWe@e
%dY<=x#b
xNbPsoK
} yiO.z
F8apH{&t
50={%R
public String getSSiteURL() k-}b{
{ 8Ac:_Zg
return sSiteURL; sM9+dh
} ^`G}gWBx}w
l]5w$dded~
O?|gp<=d
public void setSSiteURL(String value) _8E/)M
{ &%-73nYw
sSiteURL = value; N ,z6y5Lu
} G.UI|r/Kz
IC7M$
[Vma^B$7Vj
public String getSFilePath() ,{mCf^
{ ?Ec7" hK
return sFilePath; f`Fi#EKT
} zE_i*c"`
Gh}*q|Lz
ukUGvK
public void setSFilePath(String value) v\{!THCSh
{ vuYSVI2=H
sFilePath = value; O6OP =K!t:
} Er{>p|n=
yNTK .
ej"+:."\e
public String getSFileName() 0vw4?>Jf@
{ VTH> o>g
return sFileName; >qF CB\(
} ^- d%r
-(=eM3o-9m
J Px~VnE%%
public void setSFileName(String value) yYfsy?3
{ hyFyP\u]
sFileName = value; z5YWt*nm
} -jiG7OL
OtNd,U.dE
1 9CK+;b
public int getNSplitter() RVQh2'w
{ &e!7Z40w@&
return nSplitter; SBS3?hw
} bR)(H%I
.*)2SNH
a8UwhjFO
public void setNSplitter(int nCount) 7K98#;a)5
{ zld#qG6
nSplitter = nCount; c.e2M/
} i,/0/?)*_
} NN?`"Fww
gp\<p-}
uu>Pkfo
/* @8I4[TE
**Utility.java ;N?]eM}yf
*/ p|p l
package NetFox; w}YlVete
Nb'''W-iu
]'=)2 .}
public class Utility { W}mn}gTQ
>: g3k
R)m'lMi|
public Utility() \r+8qC[,
{ XY3v_5~/1F
ZNvEW
"9Q40w\
} =D<PVGo9
$[a8$VY^Cm
//线程睡眠 0a XPPnuX
public static void sleep(int nSecond) ]Yn_}Bq
{ SR|`!
try{ @/ohg0
Thread.sleep(nSecond); P&^;656r
} *(T:,PY
catch(Exception e) /$p6'1P8
{ R1$:~p2m
e.printStackTrace (); t!_<~
} ElW~48
} x5-}h*
S;286[oq@
//日志 Rx=>6,)'
public static void log(String sMsg) lUMS;H(
{ fUA uqfj[
System.err.println(sMsg); 1`qMj0Y_
} IvtJ0
U ^5Kz-5.
_ =VqrK7T
public static void log(int sMsg) vkEiOFU!u
{ sW'2+|3"
System.err.println(sMsg); +Z!)^j
} .Z `av n
} hRD=Y<>A
M:[ %[+6
I7n"&{s"*
/* (<xfCH F5
**TestMethod.java EWkLXU6t
*/ r w2arx
package NetFox; FWG6uKv
3@$,s~+ 3
VoWNW
public class TestMethod { jk[1{I/
AW!?"xdZ
:fZ}o|t7
public TestMethod() QLiu2U o
{ ///xx/weblogic60b2_win.exe 8y.wSu
try{ !C3MFm{B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |es?;s'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ($;77fPR
SiteFileFetch fileFetch = new SiteFileFetch(bean); `-J%pEIza
fileFetch.start(); i/`m`qdg
} VyXhl;
catch(Exception e){e.printStackTrace ();} .yqM7U_
f=r<nb'H
-~v2BN/
} R\G0'?h >
bU2Z[sn.
][+#;avU
public static void main(String[] args) v,-HU&/*B
{ xqG[~)~
new TestMethod(); $!-c-0ub
} R6kD=JY/!
} J\:R|KaP<p
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