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)); @c!67Z
} L%d?eHF
for(int i=0;i<nEndPos.length-1;i++) 12PE{Mut
{ lDU:EJ&DHE
nEndPos = nStartPos[i+1]; h<K;VpL6
} N ]7a=
nEndPos[nEndPos.length-1] = nFileLength; -HsBV>C
} iFCH$!
} (<C%5xk
6h_k`z
|<|,RI?
//启动子线程 0:Y`#0qK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <u?hdwW\
for(int i=0;i<nStartPos.length;i++) \.1b\\
{ #@6L|$iX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N`Xnoehu
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Cj1UD;
nStartPos,nEndPos,i); B^(rUR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *wB-lg7%
fileSplitterFetch.start(); ,A!e"=HF
} b<(UmRxx3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jN}7BbX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ePpK+E[0Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~9 WJrRWB
nEndPos = " + nFileLength); 3t8H?B12ow
// fileSplitterFetch[nPos.length-1].start(); /Z " 4[
/C"s_:m;3
D Ok^ON
//等待子线程结束 aaugu.9
//int count = 0; ]A]E)*
//是否结束while循环 70 UgKE
boolean breakWhile = false; RpK,ixbtA+
7 3z Y^x
*@arn Eu
while(!bStop) ~}0hN]*G
{ .&x?`pER
write_nPos(); -mHhB(Td'
Utility.sleep(500); z{3%Hq
breakWhile = true; /Tf*d>Yh;
0*;9CH=BE
:5K~/=6x
for(int i=0;i<nStartPos.length;i++) q&$0i
{ CotMV^
if(!fileSplitterFetch.bDownOver) y [9}[NMZ
{ A%*DQ1N
breakWhile = false; To8v#.i
break; }Q=se[((
} M}oj!xGB
} c^Gwri4
if(breakWhile) N"x\YHp
break; ms\/=96F
FJ%R3N\
#oroY.o
//count++; (bFWT_CChz
//if(count>4) i)=89?8
// siteStop(); l6B^sc*@
} gqdB!l4
=E}%>un
`{|}LFS>
System.err.println("文件下载结束！"); eN<pU%7
} \m~\,em
catch(Exception e){e.printStackTrace ();} jbhJ;c:
} x\bRj>%(
1xdESorX(
_IKP{WNB
//获得文件长度 G2+)R^FSC
public long getFileSize() D@(M+u9/%
{ v*'iWHCl,
int nFileLength = -1; ioY\8i
try{ S7NnC4)=-f
URL url = new URL(siteInfoBean.getSSiteURL()); BQuliX&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8@W/43K8-
httpConnection.setRequestProperty("User-Agent","NetFox"); `^bvj]>l
d+m6-4[_k
VVQ74b
int responseCode=httpConnection.getResponseCode(); (_&V9vat=
if(responseCode>=400) (-'0g@0UA
{ 1[/$ZYk:
processErrorCode(responseCode); d[RWkk5
return -2; //-2 represent access is error n|mJE,N
} :YJ7J4
[%iUg\'7d
&X]=Qpl
String sHeader; ,4>WLJDo
BtpjQNN
n#^?X
for(int i=1;;i++) 6KCCbg/
{ :&1=8^BY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nA_ zP4
//Utility.log(in.readLine()); A D}}>v
sHeader=httpConnection.getHeaderFieldKey(i); kk/+Vx~
if(sHeader!=null) %j[LRY/
{ nhQ44qRgQ
if(sHeader.equals("Content-Length")) AeY$.b
{ Bsu=^z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ! F;<xgw
break; D=82$$
} RdvPsv}D
} y800(z
else S QM(8*:X
break; *t?~)o7
} J+cAS/MYX
} SZK)q
catch(IOException e){e.printStackTrace ();} 4gv.E 0Fo
catch(Exception e){e.printStackTrace ();} yYG3/Z3u5
d#vSE.&
3!"b guE
Utility.log(nFileLength); u_p7Mcb
+Jo 3rX'`
Vyq#p9Q
return nFileLength; hP4)8>
} rAlh& ?X
i!.I;@
Wlr&g xZ
//保存下载信息（文件指针位置） ET,0ux9F
private void write_nPos() %Vw|5yA4
{ X@bn??
try{ QWzOp\+
output = new DataOutputStream(new FileOutputStream(tmpFile)); .o\;,l2
output.writeInt(nStartPos.length); \`P2Yq
for(int i=0;i<nStartPos.length;i++) clq~ ;hx
{ 9+'@
// output.writeLong(nPos); M}=s3[d(,
output.writeLong(fileSplitterFetch.nStartPos); h+B'_`(
output.writeLong(fileSplitterFetch.nEndPos); 5D]30
} l`v +sV^1
output.close(); _>gXNS r4u
} '&.)T2Kw
catch(IOException e){e.printStackTrace ();} g:uvoMUD
catch(Exception e){e.printStackTrace ();} a+YR5*&[OO
} 9zoT6QP4
-TK|Y"
P|e:+G7
//读取保存的下载信息（文件指针位置） rR,+G%[(=4
private void read_nPos() F=-uDtQ<N
{ (^DLCP#*
try{ WA]%,6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JVUZ}#O
int nCount = input.readInt(); F_Z&-+,*3t
nStartPos = new long[nCount]; b(.-~c('
nEndPos = new long[nCount]; Xr@l+zr
for(int i=0;i<nStartPos.length;i++) e(OwS?K
{ D4=..;
nStartPos = input.readLong(); Ism^hyL
nEndPos = input.readLong(); S+) l[0
} ?AeHVQ :C
input.close(); PwFQ#Z
} zp7V\W; &
catch(IOException e){e.printStackTrace ();} :rz9M@7
catch(Exception e){e.printStackTrace ();} 3~[`[4n^
} 1a($8>
DEUd[
`G=ztL!gq
private void processErrorCode(int nErrorCode) Ss@u,`pr
{ Xmap9x
System.err.println("Error Code : " + nErrorCode); ] ?DDCew
} Q(~3pt
3W7;f!
krQl^~@
//停止文件下载 <mv7HKVg
public void siteStop() Je#!Wd
{ #dva0%-1
bStop = true; /<3;0~#){
for(int i=0;i<nStartPos.length;i++) j!zA+hF(
fileSplitterFetch.splitterStop(); g,t3OnxS?
Veb+^&
rao</jN.9
} ?1GY%-
} ^lHb&\X
//负责部分文件的抓取 1fz*SIjG
**FileSplitterFetch.java ;;EDN45
*/ wF|0n t
package NetFox; pP|,7c5
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82j'MgGP
import java.io.*; !cq=)xR
import java.net.*; "C_T]%'Wm
+V)qep"
eV[`P&j_C
public class FileSplitterFetch extends Thread { P'a0CE%
qn2o[x
!1ML%}vvB,
String sURL; //File URL t{/hkXq]
long nStartPos; //File Snippet Start Position pwJ'3NbS
long nEndPos; //File Snippet End Position ZWf-X
int nThreadID; //Thread's ID :y=!{J<
boolean bDownOver = false; //Downing is over k_,MoDz
boolean bStop = false; //Stop identical 5h_<R!jA
FileAccessI fileAccessI = null; //File Access interface 4`'8fe/"
K^"w]ii=
I\}|Y+C$d/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z=ML(1c=
{ OJv}kwV
this.sURL = sURL; lp,\]]
this.nStartPos = nStart; RY9+ 9i
this.nEndPos = nEnd; Hu<p?mF#
nThreadID = id; BX@pt;$ek7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 285_|!.Y
} w- UKMW9"
mgy"|\]
{F'Az1^I=
public void run() 1a<]$tZk
{ J__;.rnk
while(nStartPos < nEndPos && !bStop) ykxbX
{ ,VPbUo@
+p13xc?#j
'I&|1I^
try{ ,`;jvY~Ec
URL url = new URL(sURL); RS'} nY}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HR;/Br
httpConnection.setRequestProperty("User-Agent","NetFox"); 1s Br.+p
String sProperty = "bytes="+nStartPos+"-"; D+f'*|
httpConnection.setRequestProperty("RANGE",sProperty); o:_^gJ+|
Utility.log(sProperty); sT)6nV
vT?Q^PTO
. 3GnZR,L
InputStream input = httpConnection.getInputStream(); Q(lku"U'
//logResponseHead(httpConnection); Yx6hA#7I
RXBb:f
W@l+ciZ_
byte[] b = new byte[1024]; 3@&bxYXm
int nRead; #;d)?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |</"N-#S
{ s0r"N7~
nStartPos += fileAccessI.write(b,0,nRead); ([Ebsj
//if(nThreadID == 1) fGb7=Fk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I[ai:
} Z)/6??/R
Kaf>
\@i=)dA
Utility.log("Thread " + nThreadID + " is over!"); =K:(&6f<t
bDownOver = true; \ZS\i4
//nPos = fileAccessI.write (b,0,nRead); [!G)$<
} 4RhR[
catch(Exception e){e.printStackTrace ();} +)gGs#2X
} Wdo#?@m
} (zY *0lN
,~- ?l7
v51EXf
//打印回应的头信息 M:_!w[NiLp
public void logResponseHead(HttpURLConnection con) Xtft*Z
{ 5^>n5u/
for(int i=1;;i++) ^OF5F8Tf/
{ r:-WzH(Ms
String header=con.getHeaderFieldKey(i); NH'iR!iGo
if(header!=null) mG_BM/$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <{giHT
Utility.log(header+" : "+con.getHeaderField(header)); Rvvh{U;t
else `|]e6Pb
break; }'lNi^"XL
} Q!K`e)R
} [G a~%m
B s,as
NgHpIonC
public void splitterStop() ,>u=gA&}
{ " \:ced
bStop = true; &s:=qQa1
} @;m$ua*|:
+3Y!xD?=
h'l^g%;
} ~n6[$WjZA
;-Ss# &
1~'_K9eE
/* >dk9f}7-
**FileAccess.java ('t kZt%8
*//文件访问(定位，写) >!}`%pk(
package NetFox; QsOhz
import java.io.*; -l "U"U"F
0O~p7D
YdI0E
public class FileAccessI implements Serializable{ vBNZ<L\|a
}~Q5Y3]#~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J3G7zu8
RandomAccessFile oSavedFile; _UkmYZ/
long nPos; )r9b:c\
o 7G> y#Y
I]X
public FileAccessI() throws IOException cOkgoL" 4
{ c&f y{}10
this("",0); !%xP}{(7
} '"'Btxz
[T`}yb@
nLy#|C
public FileAccessI(String sName,long nPos) throws IOException "!H@k%eAM|
{ se!mb _!
oSavedFile = new RandomAccessFile(sName,"rw"); Q.k :\m*h
this.nPos = nPos; /s c.C
oSavedFile.seek(nPos); ]>Si0%
} i[150g?K
W&(f&{A
LmQ/#Gx
public synchronized int write(byte[] b,int nStart,int nLen) Z)&D`RCf
{ =-~;OH/
int n = -1; EA|k5W*b
try{ (R'+jWH
oSavedFile.write(b,nStart,nLen); Fk1.iRVzi
n = nLen; |;u}sX1t9
} s-k_d<
catch(IOException e) z<pJYpxH
{ \cQ .|S
e.printStackTrace (); gWrAUPS[
} %y"J8;U
vG Vd
"+|L_iuNQ
return n; xNpg{cQ=
} Bf]$X>d
q* !3C
[$a<b/4
} 5|w&dM
G#[*|+f8
M=y0PCD
/* }"zC >eX&
**SiteInfoBean.java }q!_!q,@
*/ E=u/tpj
package NetFox; ;;V\"7q'
KWhZ +i`
- 8bNQU
public class SiteInfoBean { H"CUZ
6;oe=Q:Q
;GsQR+en
private String sSiteURL; //Site's URL A+ 0,i
private String sFilePath; //Saved File's Path E'c%d[:H,
private String sFileName; //Saved File's Name ;=jr0\|e
private int nSplitter; //Count of Splited Downloading File &|5GB3H=
},c,30V'
# |^^K!%
public SiteInfoBean() Cd]/
{//nSplitter的缺省值为5 GBP-V66
//default value of nSplitter is 5 ._CP% R
this("","","",5); ?4[H]BK
} :\yc*OtX
u3ZCT" !
jm3G?Vnq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pCU*@c!
{ I^3:YVR&
sSiteURL= sURL; &~-~5B|3"
sFilePath = sPath; 61_f3S(u
sFileName = sName; Vq ^]s$'
this.nSplitter = nSpiltter; !gP0ndRJ=
}/e`v6
N4UM82N
} 9z ?7{2C
;(6P6@+o
*P2[qhP2
public String getSSiteURL() |n6Eg9
{ *'R#4@wmP
return sSiteURL; A0xC,V~z
} ~ 3T,&?r
&L4 q10-N
J]pa4C`
public void setSSiteURL(String value) eThy+
{ I@ \#up}
sSiteURL = value; UQT'6* !
} .q;ED`G
Hl7:*]l7b
ijUzC>O+q
public String getSFilePath() :&VcB$
{ z4M1D9iPY
return sFilePath; ftZj}|R!
} w'ybbv{c
=AOWeLk*G
Xl%0/o
public void setSFilePath(String value) 9E1W|KE
{ IA*KaX2S<
sFilePath = value; x?r1s#88>
} K7`YJp`i
TGV
S~F`
public String getSFileName() 7#-y-B]l
{ tRfm+hqRZ
return sFileName; .FP$ IWt/1
} 8SmjZpQ?
'2^ Yw
\4bWWy
public void setSFileName(String value) v[S-Pi1
{ 'Ud|Ex@A9
sFileName = value; jO'|mGUM
} ]tt} #
?m"|QS!!K
svhrf;3:
public int getNSplitter() rPiNv 30L
{ \7Cg,Xn
return nSplitter; `l]j#qshTm
} ]=&L_(34
z,f=}t[.Y
F $yO
public void setNSplitter(int nCount) =mt?Cn}
{ CjL<RJR=
nSplitter = nCount; BzbDZV
} ,M6ZZ* ,e
} KCR N}`^
<$E6oZ
faJM^u
/* *\XH+/]+
**Utility.java RtV.d\
*/ FY#!N L
package NetFox; .y4&rF$n
?nFO:N<
"mIgs9l$
public class Utility { zlf}.
Hi,t@!!
ffcLuXa
public Utility() @}LZ! y
{ RA/EpD:H
ps1@d[n
sH!O0WL
} pP/@
')#,X^
//线程睡眠 TZB+lj1
public static void sleep(int nSecond) x8[MP?Wz
{ >bm|%Ou"
try{ Ewo~9 4{
Thread.sleep(nSecond); \e:d)^cbh
} ;j}yB
catch(Exception e) &a)vdlZSE=
{ kU*{4G|6
e.printStackTrace (); 0Xl%uF+w
} JWHSnu!
} r|R7-HI
:#X[%"g.
//日志 <+]f`c*Z
public static void log(String sMsg) q&si%
{ Je7RrCz
System.err.println(sMsg); 3fkk [U
} FLr;`3
_N#&psQzw
Dgi~rr1`'s
public static void log(int sMsg) #}yTDBt
{ 8 %Sb+w07
System.err.println(sMsg); Y& {|Sw7?
} #Ob]]!y
} T{Zwm!s
v%91k
B@K[3
/* (Wj2?k/]
**TestMethod.java -G`.y?
*/ Dz&+PES_k
package NetFox; jPJAWXB4a
v.g"{us
k*$3i
public class TestMethod { Z[L5 ;
H5xzD9K;/C
x0+glQrNN
public TestMethod() _"N\b%CkO
{ ///xx/weblogic60b2_win.exe !`wW_W
try{ Faac]5u:*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "QY1.:o<(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9]yW_]P
SiteFileFetch fileFetch = new SiteFileFetch(bean); CjZ2z%||=
fileFetch.start(); rY}B-6qJn
} b`~wGe
catch(Exception e){e.printStackTrace ();} +!O-kd
p^QZq>v
W|UtY`1
} /L~m#HxWU
hC<14
H{zPft
public static void main(String[] args) :7b-$fm
{ ;#QhQx
new TestMethod(); Y E1Hpeb
} 3LK%1+)4
} N6/T#UVns
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