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)); u%~igt@x
} GnP|x}YM
for(int i=0;i<nEndPos.length-1;i++) @+atBmt
{ J|&JD?
nEndPos = nStartPos[i+1]; rvr-XGK36\
} vN3Zr34
nEndPos[nEndPos.length-1] = nFileLength; Oft4-4$E
} -V:"l
} t3dlS`O
TLoz)&@
$Y5)(
//启动子线程 Gs3LB/8?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :n /@z4#
for(int i=0;i<nStartPos.length;i++) |&Ym@Jyj
{ 6252N]*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f4L`.~b'hb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TEDAb>
nStartPos,nEndPos,i); rj6#1kt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O(+phRwJ
fileSplitterFetch.start(); }:Z#}8
} H,N)4;F<c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =m5SK5vLKT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?_I[,N?@41
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NJNJjdD>
nEndPos = " + nFileLength); J!:SPQ
// fileSplitterFetch[nPos.length-1].start(); eds26(
4wrk2x[
XoA+MuDzpo
//等待子线程结束 sg+uBCGB
//int count = 0; }1>[
//是否结束while循环 u%.$BD Hg
boolean breakWhile = false; 0{#8',*}m?
@:KJYm[
26xXl|I
while(!bStop) yRo-EP
{ :O(^w}sle
write_nPos(); jg?x&'u\)
Utility.sleep(500); {J^lX/D
breakWhile = true; byv[yGa`
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WJ_IuX51'
for(int i=0;i<nStartPos.length;i++) ( H6c{'&
{ vap,y $C
if(!fileSplitterFetch.bDownOver) sP ls zC[
{ +|tC'gCnV
breakWhile = false; 1x[)/@.'f
break; }[M`uZ
} Yot?=T};3{
} D$T%\ P
if(breakWhile) 6P';DB
break; U^Xm)lL
tO0!5#-VR
,Jd ',>3
//count++; W^s ;Bi+Nw
//if(count>4) #lkM=lY'
// siteStop(); (&!NC[n,
} QcgfBsv96
?:w1je7
E8-P"`Qba
System.err.println("文件下载结束！"); K# Jk _"W
} F{UP;"8'
catch(Exception e){e.printStackTrace ();} e@IA20
} 5< ja3
/z}~zO
Q:5KZm[[
//获得文件长度 Ox@sI:CT
public long getFileSize() 1bH;!J
{ JJ%ePgWT
int nFileLength = -1; mW:!M!kk
try{ !H ~<
URL url = new URL(siteInfoBean.getSSiteURL()); %*\es7m}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S%Us5`sd
httpConnection.setRequestProperty("User-Agent","NetFox"); Z ,EvQ8i
)HvnoUO0
d'Zqaaf k%
int responseCode=httpConnection.getResponseCode(); ;INW`b~
if(responseCode>=400) AZmb!}m+d
{ O9r>E3-q
processErrorCode(responseCode); SCz(5[MZJ
return -2; //-2 represent access is error 2Y7)WPn
} D&S26jrZ
# 0Lf<NZ
;s52{>&F]
String sHeader; _%GGl$kH
/IsS;0K%L
.j-IX1Sa
for(int i=1;;i++) {6}eN|4~#
{ . Z%{'CC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #es9d3~\
//Utility.log(in.readLine()); AGbhJ=tB
sHeader=httpConnection.getHeaderFieldKey(i); >$ e9igwe
if(sHeader!=null) C?2'+K
{ 'z$Q rFW
if(sHeader.equals("Content-Length")) mVR P~:+
{ El@(mOu|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0)m(;>'70
break; /FIE:Io
} *<J*S#]
} phgm0D7
else l~M_S<4n
break; 2"B_At
} yfm^?G|sW
} ObiT-D?)g
catch(IOException e){e.printStackTrace ();} -UD\;D?$
catch(Exception e){e.printStackTrace ();} [B|MlrZ
3:C oZ
}6@pJG
Utility.log(nFileLength); B:+6~&,-
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w.0qp)}
return nFileLength; D)d~3`=#
} >>5NX"{
WASU0
HTyLJe
//保存下载信息（文件指针位置） B~_d^`
private void write_nPos() +mp@b942*
{ <-u8~N@43W
try{ ^Y iJV7
output = new DataOutputStream(new FileOutputStream(tmpFile)); %b"\bHH
output.writeInt(nStartPos.length); Mv6-|O
for(int i=0;i<nStartPos.length;i++) dS<C@(
{ L*~J%7
// output.writeLong(nPos); 19j+lCSvH
output.writeLong(fileSplitterFetch.nStartPos); 1Tm^
output.writeLong(fileSplitterFetch.nEndPos); T16{_
} $]/Zxd
output.close(); l'TWkQ-
} ruazOmnn~
catch(IOException e){e.printStackTrace ();} 4A2?Uhpy
catch(Exception e){e.printStackTrace ();} l@ap]R
} oD$J0{K6
.3MIcj=p
/\WQxe
//读取保存的下载信息（文件指针位置） <0PT"ij
private void read_nPos() ,.qMEMm
{ 6CMub0
try{ FGh]S-A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H `(exa:w
int nCount = input.readInt(); $O dCL
nStartPos = new long[nCount]; E,f>1meN=
nEndPos = new long[nCount]; p^'3Odd|O
for(int i=0;i<nStartPos.length;i++) L_K=g_]
{ }sOwp}FV8X
nStartPos = input.readLong(); pe{;~-|6
nEndPos = input.readLong(); y})70w@+_
} T9879[ZU\
input.close(); :bC40@
} hc'-Dh
catch(IOException e){e.printStackTrace ();} Ed ,D8ND
catch(Exception e){e.printStackTrace ();} 4M^G`WA}t9
} D7S'*;F
b/Xbs0q
ME=/|.}D<
private void processErrorCode(int nErrorCode) Vl2XDkhq
{ Rh>}rGvCUN
System.err.println("Error Code : " + nErrorCode); Ey4z.s'-l
} qvv2O1c"A
r{rQu-|.
?2g`8[">
//停止文件下载 HO''&hz
public void siteStop() tT79p.z B
{ rrCNo^W1
bStop = true; P';?YV0
for(int i=0;i<nStartPos.length;i++) @, Wvvh
fileSplitterFetch.splitterStop(); %3$*K\Ai
H8'Z#"h
DHY@akhrK
} Iy6$7~
} 6}KZp~s
//负责部分文件的抓取 '`Wwt.A
**FileSplitterFetch.java E{n:J3_X^d
*/ bk\yCt06y;
package NetFox; @S7sr-
NMi45y(Y
bcZf>:gVf
import java.io.*; jr`Ess
import java.net.*; -c}, :G"
+(+Itmx2&
7H|$4;X^
public class FileSplitterFetch extends Thread { d`(@_czdF
=lu/9 i6
@_LN3zP
String sURL; //File URL g=e71DXG2
long nStartPos; //File Snippet Start Position <Engi!
long nEndPos; //File Snippet End Position tu5*Qp\
int nThreadID; //Thread's ID H~E(JLcU
boolean bDownOver = false; //Downing is over 1Zi,b
boolean bStop = false; //Stop identical z1Ov|Q`
FileAccessI fileAccessI = null; //File Access interface |eWjYGwJa
mSo_} je(
SC- $B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UDL RCS8i
{ !S_^94b@
this.sURL = sURL; Q8_ d)t|
this.nStartPos = nStart; wGZR31
this.nEndPos = nEnd; \{EpduwZ
nThreadID = id; "hy.GWF|*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0pSmj2/,.
} STJJU]H
5j-]EJb
HdLH2+|P;D
public void run() <2nZ&M4/s{
{ 2 6>ZW4Z
while(nStartPos < nEndPos && !bStop) -<_Ww\%8M
{ ?SC[G-b
#-GJ&m8
XduV+$03
try{ Tt>8?
URL url = new URL(sURL); +z$pg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Rd>B0;4
httpConnection.setRequestProperty("User-Agent","NetFox"); a:_I
String sProperty = "bytes="+nStartPos+"-"; M5trNSL&u
httpConnection.setRequestProperty("RANGE",sProperty); A'%1ZQ33O
Utility.log(sProperty); ~M(5Ho
_fwb!T}$
0Ld@H)
InputStream input = httpConnection.getInputStream(); e*.b3z
//logResponseHead(httpConnection); VnT>K9&3
SnYLdwgl
H&yD*@
byte[] b = new byte[1024]; G5FaYL.7
int nRead; ZKdeB3D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1U,1)<z~u
{ QL$S4 J"
nStartPos += fileAccessI.write(b,0,nRead); /QEiMrz@6
//if(nThreadID == 1) 1* ]Ev
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :F?x)"WoQ+
} .uEPnzi
8j4z{+'TQ
bTSL<"(]N
Utility.log("Thread " + nThreadID + " is over!"); c1xrn4f@a
bDownOver = true; *;XWLd#
//nPos = fileAccessI.write (b,0,nRead); x{&w?ng
} w2xG_q
catch(Exception e){e.printStackTrace ();} u@3y&b
} A?*o0I
} o5n^!gi4
v-! u\
c c
//打印回应的头信息 =-o'gL
public void logResponseHead(HttpURLConnection con) W<<9y
{ ~RD+.A
for(int i=1;;i++) aSP4a+\*
{ uZi.HG{<)
String header=con.getHeaderFieldKey(i); &,.Y9; b
if(header!=null) <s@-:;9~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O,.!2wVrN
Utility.log(header+" : "+con.getHeaderField(header)); I_q~*/<h
else >\!4Mk8
break; Bu]t*$
} LA[g(i 7
} jp+_@S>
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dr<<!q /
public void splitterStop() i7LJ&g/)
{ cUO<.
bStop = true; {ccIxL /~
} 7_# 1Ec|;
4c+$%pq5
tW;:-
} }Up.){.%
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mw^7oO#
/* Y[SU&LM
**FileAccess.java |/ }\6L]
*//文件访问(定位，写) y3<Y?M4
package NetFox; 1h7+@#<:a
import java.io.*; ]/cd;u
n$(p-po
|7@O($b
public class FileAccessI implements Serializable{ _u}4j9T
Yif*"oO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :h,`8 Di
RandomAccessFile oSavedFile; ^JR;epVJ
long nPos; A%\tiZe
J`*iZvW#Bx
Q# ?wXX47
public FileAccessI() throws IOException M=]5WZO~A
{ X_$a,"'~)
this("",0); ; "3+YTtp
} ~np,_yI
nNmsr=y5
=IKEb#R/
public FileAccessI(String sName,long nPos) throws IOException oK9'
{ yGpz,X4x
oSavedFile = new RandomAccessFile(sName,"rw"); y]e>E
this.nPos = nPos; =xianQ<lK
oSavedFile.seek(nPos); M|io4+sy
} l =IeJh
y}08~L?2
0D~ C 5}/4
public synchronized int write(byte[] b,int nStart,int nLen) tD$lNh^
{ 2-0$FQ@/
int n = -1; +1 eCvt:,
try{ Ejq#~Zhr!
oSavedFile.write(b,nStart,nLen); kVS?RHR
n = nLen; Ov82ibp_1
} #2xSyOrmf
catch(IOException e) ;o<m}bGaT
{ Tx%VU8\?n
e.printStackTrace (); b @;.F!x
} pe&UQ C^
]=F8p2w?
fMf&?`V
return n; kJ)gP2E
} o0z67(N&g
W2wpcc
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} nkeI60
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UF__O.l__
/* ]|:uU
**SiteInfoBean.java vs&8wbS)
*/ _U)%kY8
package NetFox; iz]rFNR
9j|gdfb%ml
%zo= K}u
public class SiteInfoBean { l+y-Fo@
34|a:5c
4-v6=gz.
private String sSiteURL; //Site's URL 5 ZfP
private String sFilePath; //Saved File's Path Me:{{-V4
private String sFileName; //Saved File's Name ?PPZp6A3L=
private int nSplitter; //Count of Splited Downloading File v@EQ^C2.&
T,JA#Rk|1N
UmKX*T9
public SiteInfoBean() ?HR%bngK
{//nSplitter的缺省值为5 X21dX`eMN
//default value of nSplitter is 5 $1*3!}_0
this("","","",5); gH:ArfC
} Wf>^bFb"$
t0m*PJcF
x|~zHFm6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $GF]/;\m
{ 5@u~3jPd
sSiteURL= sURL; ^O%9yEo
sFilePath = sPath; $;D* n'8Fx
sFileName = sName; ;8B.;%qkL
this.nSplitter = nSpiltter; X,v4d~>]
msk/p>{O
$->d!
} Q1tpCT
6/mF2&&g
%(LvE}[RJ
public String getSSiteURL() Ygkv7>?,
{ ^abD!8
return sSiteURL; );}t&}
} mrZ`Lm#>pS
,-rB=|w
]HvZ$
public void setSSiteURL(String value) [6gO
{ h{]#ag5`
sSiteURL = value; w+f=RHX"{
} QD<eQsvV
jQtSwVDr
:%tuNJjj
public String getSFilePath() y@apJ;_R-
{ v:d9o.h
return sFilePath; Q~ 0Dfow?
} 68x}w Ae
MTmO>V&O
qa!RH]B3
public void setSFilePath(String value) ^9ng)
{ 2@MN]Low
sFilePath = value; Jgi Iq
} (@]tG?I=
H=.K
+8^_D?*\n
public String getSFileName() ^g!B.ll`
{ vg^Myn
return sFileName; :)P<jX-G
} ,$Tk$
Vm!i
eoJ]4-WFq
public void setSFileName(String value) \p6 }
{ v["3
sFileName = value; wOHEv^,
} .s};F/(diD
Bxv8RB
H~m]nV,r
public int getNSplitter() #AncOo
{ u7muaSy
return nSplitter; `-D$Fsl
} VG#Q;Xd}
V.,bwPb{9
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public void setNSplitter(int nCount) FDq{M?6i
{ (2%>jg0M
nSplitter = nCount; 5\G)Q<A]*L
} ~t9Mh^gij
} ? ICDIn
/J;]u3e|
k!13=Gh
/* fq Y1ggL
**Utility.java p\+6"28{_~
*/ pF='jj51
package NetFox; pbdF]>\
#`j][F@N
t F/nah
public class Utility { (9z|a,
^Fp=y,D
,o)4p\nV
public Utility() VR v02m5
{ AM?Ec1S #a
lJj&kVHb
MOLO3?H(
} ji##$xC
!Mil?^
//线程睡眠 _m7co :
public static void sleep(int nSecond) {]M>Y%j48
{ )G4rJ~#@
try{ ;KS`,<^-
Thread.sleep(nSecond); ;fx1!:;.
} ]Wy.R6
catch(Exception e) (j=DD6fC
{ hfh.eL
e.printStackTrace (); x3;jWg~'
} xPvRQ
} x@ 6\Ob
Jy`G]]?
//日志 DvJB59:_}
public static void log(String sMsg) eE,;K1
{ J=P;W2L
System.err.println(sMsg); pe#*I/)b
} Yhk6Uog{4
2+&R"#I
tnL."^%A2I
public static void log(int sMsg) 1g81S_T .
{ gA"<MI'y
System.err.println(sMsg); +{Gw9h"5g*
} N&N 82OG
} <O bHf`Q
M1gP R
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/* =N;$0Y(g
**TestMethod.java fOJj(0=y
*/ NlMQHma
package NetFox; ,W8au"
:@WLGK*u.
Fu mn9
public class TestMethod { @92gb$xT
uc\.oG;~q
Hp*gv/0
public TestMethod() Es~DHX
{ ///xx/weblogic60b2_win.exe >&[3
try{ Q~h6J*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QglYU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hOl=W |)v
SiteFileFetch fileFetch = new SiteFileFetch(bean); `:R-[>5P8
fileFetch.start(); F\Y,JUn[G
} bWUS9WT
catch(Exception e){e.printStackTrace ();} fX""xTNPi
{ $X X
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} \ bC}&Iz6
Kj=;>u
RAdvIIQp:
public static void main(String[] args) T[m ~6
{ Q{8qm<0g
new TestMethod(); SUo^c1)G
} +=Yk-nJ
} GtG&yeB
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