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)); tik*[1it
} V#$QKn`;
for(int i=0;i<nEndPos.length-1;i++) g)Hsd0
{ xV+\R/)x
nEndPos = nStartPos[i+1]; Mx,5
} +Eb-|dM
nEndPos[nEndPos.length-1] = nFileLength; tgCp2`n
} "4WnDd5"
} Ih5Y7<8b~
#y#TEw,
<7ANXHuSW
//启动子线程 ^kcuRJ0*$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yw+]S
for(int i=0;i<nStartPos.length;i++) vA:ZR=)F
{ t*Ro2QZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cu?6\@cD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'qiAmaX
nStartPos,nEndPos,i); 5s^vC2$)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ulN1z
fileSplitterFetch.start(); N9d^;6;i
} ?+=,t]`!m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <!G /&T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8d'/w}GV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :,p3&2I
nEndPos = " + nFileLength); LEnv/t6U
// fileSplitterFetch[nPos.length-1].start(); @eBo7#Zr
1r.2bL*~jw
dbEXlm
//等待子线程结束 @+M1M2@Xz
//int count = 0; -,/6 Wn'j
//是否结束while循环 rT;l#<#VE
boolean breakWhile = false; ,ynN801\m
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/J-.K*xKt
while(!bStop) |QbCFihn
{ g8Y)90 G
write_nPos(); Vo{ ~D:)
Utility.sleep(500); `xv Uq\
breakWhile = true; zBTxM
z<A8S=s6n
U<XfO'XJ
for(int i=0;i<nStartPos.length;i++) I31Nu{
{ 7!`1K_v6
if(!fileSplitterFetch.bDownOver) 0nI*9
{ T<nK/lp1t
breakWhile = false; 4$2HO`@uN
break; ''9K(p6
} j4@6`[n:
} `{w|2 [C3
if(breakWhile) v%`k*n':
break; &u"mFweS
`3K."/N6c
%y>*9$<pXe
//count++; >3p8o@:
//if(count>4) %|/\Qu
// siteStop(); e5FF'~A%]
} U[yA`7Zs}
_8`S&[E?
k?3mFWc
System.err.println("文件下载结束！"); ~|{e"!(}
} buKkm$@w
catch(Exception e){e.printStackTrace ();} @Py'SH!-
} rWM5&M
-ImO y|
)99^58my
//获得文件长度 Bz,Xg-k+
public long getFileSize() W1M Bk[:Q
{ 4rCw#mVtB
int nFileLength = -1; ~:C`e4
try{ NQ '|M
URL url = new URL(siteInfoBean.getSSiteURL()); SZxnYVY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $RRh}w\0^
httpConnection.setRequestProperty("User-Agent","NetFox"); |a0@4 :
bWCtRli}
>"zN`
int responseCode=httpConnection.getResponseCode(); X"f]
if(responseCode>=400) .)t*!$5=N
{ $G/p[JG6-
processErrorCode(responseCode); @Ko}Td&E(
return -2; //-2 represent access is error l~1l~Gx_&n
} ZS&+<kGD
,k:>Z&:
oC!z+<
String sHeader; gazX2P[D
Q`=d5Uvw
eY:jVYG(
for(int i=1;;i++) RbA.&=3
{ 3P'Wk|j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c/-'^+9
//Utility.log(in.readLine()); *'@T+$3s
sHeader=httpConnection.getHeaderFieldKey(i); u3 4.
if(sHeader!=null) +=kz".$
{ IV`+B<3
if(sHeader.equals("Content-Length")) *u>[
{ '_n$xfH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~f8:sDJ
break; A22'qgKm@
} @Rqn&tA8
} 99Nm?$g
else :{#w-oC>6P
break; qHYoQ.ke
} ^{O1+7d[.
} ir;az{T#U
catch(IOException e){e.printStackTrace ();} ^"J)^3j<
catch(Exception e){e.printStackTrace ();} 40;4=
w[;5]z
|s !7U
Utility.log(nFileLength); H|d"45J_
$)jf
s";9G^:
return nFileLength; #t&L}=G{%
} ]n4G]ybK%
=|3*Y0
>Cglhsb:N
//保存下载信息（文件指针位置） Ij7[2V]c
private void write_nPos() 8SO(pw9
{ E*UE?4FSw|
try{ $_W kI^
output = new DataOutputStream(new FileOutputStream(tmpFile)); jH2_Ekgc;_
output.writeInt(nStartPos.length); OGnuBK
for(int i=0;i<nStartPos.length;i++) YGCBDH%6
{ Cfst)[j
// output.writeLong(nPos); =zwn3L8fL
output.writeLong(fileSplitterFetch.nStartPos); C.=[K_
output.writeLong(fileSplitterFetch.nEndPos); z7O$o/E-*
} \ UiITP<
output.close(); 89%#;C
} J4m2|HK
catch(IOException e){e.printStackTrace ();} y-a3
catch(Exception e){e.printStackTrace ();} 2fMKS
} >B+!fi'SS>
t`"pn<
0-IL@Di`F
//读取保存的下载信息（文件指针位置） 0{.[#!CSk
private void read_nPos() D~t
{ !s[[X5
try{ O g!SFg*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :z%q09.)
int nCount = input.readInt(); 6{?B`gm7g
nStartPos = new long[nCount]; 7NQEnAl
nEndPos = new long[nCount]; 9<1dps=c
for(int i=0;i<nStartPos.length;i++) Hus.Jfam
{ AP/#?
nStartPos = input.readLong(); ;a~ e
nEndPos = input.readLong(); Ox&]{
} t,308Z
input.close(); )cBO_
} 18G=j@k7
catch(IOException e){e.printStackTrace ();} 9 kLA57
catch(Exception e){e.printStackTrace ();} yuq2)
} klx28/]
s73'h
Ew*SA
private void processErrorCode(int nErrorCode) `E8D5'tt
{ XWq@47FR
System.err.println("Error Code : " + nErrorCode); `]wk)50BVp
} LHd9q^D
}5lC8{wZ
K4Hu0
//停止文件下载 -$cO0RSY
public void siteStop() i^"!"&tW#
{ o&#!W(
bStop = true; m,PiuR>
for(int i=0;i<nStartPos.length;i++) =&roL7ps
fileSplitterFetch.splitterStop(); QEc4l[^{.B
J)P7QTC
28LYGrB
} #.@-ng6C
} 5N:IH@
//负责部分文件的抓取 #X qnH
**FileSplitterFetch.java w L4P-4'
*/ nG0R1<
package NetFox; c[a^fu!
>- U+o.o
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import java.io.*; y'm5Z-@o6
import java.net.*; e$o]f"(
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public class FileSplitterFetch extends Thread { t {H{xd
t:*1*;
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String sURL; //File URL 5Kw?#
long nStartPos; //File Snippet Start Position PP8627uP
long nEndPos; //File Snippet End Position %BF,;(P
int nThreadID; //Thread's ID }mpFo2
boolean bDownOver = false; //Downing is over 4|;Ys-Q
boolean bStop = false; //Stop identical 1H \
FileAccessI fileAccessI = null; //File Access interface iAZbh"I
YFP<^y=
JJy.)-R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Lr0:yo
{ D.gD4g_O/
this.sURL = sURL; HJJ;gTj
this.nStartPos = nStart; &pW2R}
this.nEndPos = nEnd; 17-B'Gl!<%
nThreadID = id; \&[(PNl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;.=]Ar}
} ehTv@2b
&z@}9U*6b
/h8100
public void run() +QP(ATdM
{ NuW6~PV
while(nStartPos < nEndPos && !bStop) J vq)%t8q>
{ D7=Irz!O\7
opTH6a
X.ecA`0
try{ #n]K$k>
URL url = new URL(sURL); S_?sJwM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }46Zfg\T6n
httpConnection.setRequestProperty("User-Agent","NetFox"); 3n~O&{
String sProperty = "bytes="+nStartPos+"-"; 6j95>}@
httpConnection.setRequestProperty("RANGE",sProperty); }42Hhu7j
Utility.log(sProperty); RK=Pm7L:`y
i|m8#*Hd
\>||
InputStream input = httpConnection.getInputStream(); &4ndi=.#rg
//logResponseHead(httpConnection); mZO-^ct4
LW k/h1
'KDt%?24
byte[] b = new byte[1024]; -fp/3-
int nRead; BS(jC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cbl>:ev1h
{ %7QSBL
nStartPos += fileAccessI.write(b,0,nRead); QAAuFZs
//if(nThreadID == 1) En)Ptz#0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %J Jp/I
} R+z'6&/ =I
;M~9Yr=1
#<X4RJ
Utility.log("Thread " + nThreadID + " is over!"); (V1;`sI8
bDownOver = true; ^+~5\c*
//nPos = fileAccessI.write (b,0,nRead); (H"{r
} :s\zk^h?
catch(Exception e){e.printStackTrace ();} }ice*3'3
} $B7c\MR j
} .)=*Yr M
iJj!-a:z.
EIfqRRTA
//打印回应的头信息 {~w(pAx
public void logResponseHead(HttpURLConnection con) _>BYUPY
{ w]nt_xj
for(int i=1;;i++) `wZ
{ RN|Bk
String header=con.getHeaderFieldKey(i); w,up`W7,
if(header!=null) Ijap%l1I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (EvYrm4
Utility.log(header+" : "+con.getHeaderField(header)); :J_UXtx
else DBG0)=SHy
break; kvuRT`/
} yf!7 Q>_G^
} %hN(79:g
EZ:? (|h
Y652&{>q
public void splitterStop() wVFa51a)yy
{ dNY'uv&Y
bStop = true; {to(?`Y
} M$.bC0}T
*xmC`oP
|vm-(HY!
} :3XvHL0rx
H C,5j)1
xf/K+
/* uD?RL~M
**FileAccess.java EpKZ.lCU
*//文件访问(定位，写) \!30t1EZ
package NetFox; -s!J3DB
import java.io.*; 3 !8#wn
GD)paTwO<
)B+o F7
public class FileAccessI implements Serializable{ qoH:_o8ClO
7Ok-T10
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `GBJa k
RandomAccessFile oSavedFile; ,/GFD[SQ
long nPos; !vRN'/(Vyu
rir,|y,
jD"nEp-
public FileAccessI() throws IOException @%2crJnkS
{ @(oY.PeS<z
this("",0); p/Q< VV
} BeQ'\#q,
g.Qn,l]X/p
;<[!;8
public FileAccessI(String sName,long nPos) throws IOException xu"-Uj1
{ !`7evV:
oSavedFile = new RandomAccessFile(sName,"rw"); dc4XX5Z
this.nPos = nPos; ME]7e^
oSavedFile.seek(nPos); 0PFC%x
} #K@!jh)y^
"N_@q2zF
Iurz?dt4w
public synchronized int write(byte[] b,int nStart,int nLen) mZ? jpnd
{ 2?Ryk`2i)
int n = -1; ]j,o!|rx7
try{ g8&& W_BI
oSavedFile.write(b,nStart,nLen); g'T L`=O
n = nLen; I]5){Q"S
} #Pz'-lo
catch(IOException e) H(--hG5}
{ ow 6\j:$?
e.printStackTrace (); }*%=C!m4R!
} J0e^v
oNl-!W
K iXD1Zpz
return n; 0QquxYYw,
} "30=!k
2uY:p=DxG9
ak3WER|f#
} ZJGIib
%jq R^F:J
v6aMYmenBH
/* jL5O{R[ x:
**SiteInfoBean.java Vu~fF@ |
*/ }V.fY3J-
package NetFox; -~\7ZRP8
6rG7/
"FGgem%9
public class SiteInfoBean { wT;;B=u}G
#\Q)7pgi.
9S'\&mRl
private String sSiteURL; //Site's URL P??pWzb6HH
private String sFilePath; //Saved File's Path kaEu\@%n
private String sFileName; //Saved File's Name .g}Y! l
private int nSplitter; //Count of Splited Downloading File 1ATH$x
tC f@v'1t
[vY)y\W{
public SiteInfoBean() b^8"EBo
{//nSplitter的缺省值为5 @.`HvS
//default value of nSplitter is 5 (lit^v,9
this("","","",5); 3+U2oI:I
} >i61+uzEd+
ov!L8 9`[u
,<OS:]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #&{)`+!"
{ OQuTM[W
sSiteURL= sURL; =PLy^%
sFilePath = sPath; g8"{smP/
sFileName = sName; mn{R>
this.nSplitter = nSpiltter; X)9|ZF2`
W"xRf0\V
Hpp;dG
} 9x8Ai
!$o9:[B
<lPHeO<^]
public String getSSiteURL() aO\@5i_r
{ Gh'{O/F4*
return sSiteURL; bV@5B#] 2R
} `5~<)
O}lqY?0*
)7rMevF(xJ
public void setSSiteURL(String value) Qm?o^%a
{ zjx'nK{eI
sSiteURL = value; 1;MUemnx`
} UZc{ Av
cC,gd\}M
(W`=`]!
public String getSFilePath() ;wr]_@<~
{ :4238J8
return sFilePath; >LR+dShG
} kca Y
w{ x=e
iJu$&u
public void setSFilePath(String value) RveMz$Yy
{ 'cbD;+YH
sFilePath = value; /lvH p
} Aa%ks+1
/#?i+z
]p~,C*UH0
public String getSFileName() JvLa@E)
{ r\{; ~V
return sFileName; gB#$"mq,
} d4-cZw}+
(KG>lTdN
B3Esfk
public void setSFileName(String value) 3sGe#s%
{ ,b8B)VZ?
sFileName = value; = P{]3K
} -U_<:
jvos)$;L-
30/(
public int getNSplitter() !.k
{ )u'("
return nSplitter; 0IjQqI
} %!1:BQ,p,i
Nb;Yti@Y.
niN$!k+Jr
public void setNSplitter(int nCount) =Wk!mGc
{ >?A3;O]
nSplitter = nCount; E>?T<!r~j
} x:Kca3pv_
} 5gbJTh<JU
#S4{,
l*yJU3PW
/* C"ZCX6p+$
**Utility.java Lw.N3!e[
*/ SuW_[6]
package NetFox; `795K8
O<h`[1eUjS
l4d2i;4BK
public class Utility { R3$eq )
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k^.9;FmQ
public Utility() ,*V{gpC7
{ 5X-cDY*|
l>M&S^/s j
ZUMzWK5Th
} ^@`dsll
A_@#V)D2
//线程睡眠 (byFr9z
public static void sleep(int nSecond) \^3\_T&6
{ T;}pMRd%
try{ ZuF-$]oL&
Thread.sleep(nSecond); ([ xYOxcp5
} t{K1ht$[:
catch(Exception e) mi3yiR
{ m`-{ V<(M
e.printStackTrace (); avk0pY(n
} b07 MTDFH7
} nlK"2/W
r!etj3
//日志 [3rvRJ.
public static void log(String sMsg) V4Ql6vg_f
{ dM7-,9Vc
System.err.println(sMsg); [>4Ou^=1
} bY;ah;<
dGcG7*EX
h5ST`jZ
public static void log(int sMsg) $}7/mS@c
{ #IyxH$
System.err.println(sMsg); j#0@%d
} pNI=HHx
} H{`S/>)[
s&!g )
4?,N;Q
/* 2|Hq[c=~
**TestMethod.java B9n$8QS
*/ {KE858
package NetFox; =x9zy]
p^A9iieHp=
u-At k-2M
public class TestMethod { WeE>4>^
*K'(t
ZPY#<^WOzr
public TestMethod() vWcU+GBZI
{ ///xx/weblogic60b2_win.exe ?x"<0k1g
try{ tD.md_E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kA{[k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iXMs*GcK
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4WZ:zr N
fileFetch.start(); vu;pILN
} V,fSn:8%M
catch(Exception e){e.printStackTrace ();} B_anO{3$4
yNP M-
#)2'I`_E
} lphQZ{8
kcVEE)zb
L\XnTL{
public static void main(String[] args) aRdzXq#x
{ 9sifc<za
new TestMethod(); [84ss;.$
} &p%0cjg"Q
} %Iw6oG
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