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)); fDU!~/#
} W]5w \
for(int i=0;i<nEndPos.length-1;i++) 7Da`
{ o$lM$E:
nEndPos = nStartPos[i+1]; d,n 'n
} ]F'e aR
nEndPos[nEndPos.length-1] = nFileLength; >e[i5
} P! #[mio
} [}0haTYc4
hp-<2i^"!
(S\[Y9
//启动子线程 l#Y,R 0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y ~!Zg}o
for(int i=0;i<nStartPos.length;i++) k5.Lna
{ DwE[D]7o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _C[q4?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XXn67sF/
nStartPos,nEndPos,i); ~;{;,8!)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CD( :jM?
fileSplitterFetch.start(); MC.)2B7
} uH- l%17
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cl8Cg~2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /zVOK4BqN+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {dMsz
nEndPos = " + nFileLength); }.m<
// fileSplitterFetch[nPos.length-1].start(); G[I"8iS,
MPg)=LI
EC!02S
//等待子线程结束 W_(j3pV?Ml
//int count = 0; lbl?k5
//是否结束while循环 9BBmw(M}
boolean breakWhile = false; o5uph=Q{
BdblLUGK#
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while(!bStop) " h~Zu
{ tKx~1-
write_nPos(); Nk VK
Utility.sleep(500); ]e>w}L(gV
breakWhile = true; }1i`6`y1
4,gK[ dc
][h%UrV
for(int i=0;i<nStartPos.length;i++) Yz"#^j}Kg
{ /saIs%(fU
if(!fileSplitterFetch.bDownOver) aPfO$b:
{ tla 5B_
breakWhile = false; QIvVcfM^
break; hl(hJfp
} ju8q?Nyhs
} ujq=F
if(breakWhile) BBRR)
break; )E@.!Ut4o
i&66Fi1
>j(_[z|v3
//count++; `nv~NLkl
//if(count>4) 7#ibN!
// siteStop(); 5Y'qaIFR
} |w1Bq
_j/<{vSy
JG!mc7
System.err.println("文件下载结束！"); w?k>:,'[
} zrL$]Oy}x
catch(Exception e){e.printStackTrace ();} K&ZtRRDd
} %.Fi4}+O
&5spTMw8
rc>4vB_ha
//获得文件长度 wh\}d4gN
public long getFileSize() +]A:M6P:{v
{ ]&xk30
int nFileLength = -1; EQyC1j
try{ { MSkHf=
URL url = new URL(siteInfoBean.getSSiteURL()); 4Lh!8g=/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '()xHEGl3
httpConnection.setRequestProperty("User-Agent","NetFox"); N^ds RYC
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c~$)UND^
int responseCode=httpConnection.getResponseCode(); Ins`l
if(responseCode>=400) KL:j?.0
{ ~xfP:[u
processErrorCode(responseCode); 3yY}04[9<
return -2; //-2 represent access is error Lh"<XYY
} ?(y*nD[a
HU}7zK2
1onM j
String sHeader; i]y<|W)Q3
.hP D$o
.b&t;4q
for(int i=1;;i++) t#/YN.@r
{ *{@Nq=fE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TJpD{p}
//Utility.log(in.readLine()); ;|5F[
sHeader=httpConnection.getHeaderFieldKey(i); 2c,9e`
if(sHeader!=null) G<8/F<m/
{ bv9]\qC]T<
if(sHeader.equals("Content-Length")) $s c
{ N/'b$m5= S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gQelD6c
break; OU(8V^.
} eRstD>r
} Uq,^Wy
else +I:Unp
break; x{8xW0
} Nw/ ku
} E`0?
catch(IOException e){e.printStackTrace ();} |'8Nh
catch(Exception e){e.printStackTrace ();} ]z;I_-
)?naN
4qbBc1,7y
Utility.log(nFileLength); ]G=L=D^cK
<QAFL uey
7P5)Z-K[
return nFileLength; 4qh?,^Dq
} b:m88AG
VUGmi]qd
6|%?tex
//保存下载信息（文件指针位置） m@F`!qY~Y\
private void write_nPos() fS:&Ak ];
{ S9D<8j^
try{ ~i{(<.he
output = new DataOutputStream(new FileOutputStream(tmpFile)); AW'0,b`v
output.writeInt(nStartPos.length); e8!5I,I
for(int i=0;i<nStartPos.length;i++) =tn)}Y.<e
{ Jbg/0|1
// output.writeLong(nPos); ,vawzq[oSy
output.writeLong(fileSplitterFetch.nStartPos); ww3-^v
output.writeLong(fileSplitterFetch.nEndPos); NC`aP0S
} S-b/S5
output.close(); <CiSK!
} 1~`fVg
catch(IOException e){e.printStackTrace ();} @6sqMw}
catch(Exception e){e.printStackTrace ();} 9c'xHO`
} b<ZIWfs
OU.6bmWy|
Tc:)- z[o
//读取保存的下载信息（文件指针位置） }W8;=$jr
private void read_nPos() -p-ZzgQ
{ 3m)0z{n
try{ \fdv]f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6]N;r5n
int nCount = input.readInt(); fu ,}1Mq#
nStartPos = new long[nCount]; 1{.|+S Z!
nEndPos = new long[nCount]; ,HV(l+k {|
for(int i=0;i<nStartPos.length;i++) e}7lBLK]*
{ RJ&RTo
nStartPos = input.readLong(); ^*Q ?]N
nEndPos = input.readLong(); vWv"
} xml7Uarc
input.close(); y9GoPC`z
} h"Q8b}$^)
catch(IOException e){e.printStackTrace ();} `25yE/
catch(Exception e){e.printStackTrace ();} MrFQ5:=
} 3M7/?TMw{6
>Q;l(fdj
W,n!3:7s
private void processErrorCode(int nErrorCode) _8J.fT$${
{ Eyqa?$R
System.err.println("Error Code : " + nErrorCode); CwzZ8.o$i
} $( kF#
,^< R{{{-A
ZJJY8k `
//停止文件下载 1(R}tRR7R
public void siteStop() pE0Sw}A:9
{ %)1?TU
bStop = true; AeM^73t
for(int i=0;i<nStartPos.length;i++) "+nRGEs6
fileSplitterFetch.splitterStop(); lb3bm)@:
t%)7t9j
\?-<4Bc@
} _J#zY-j
} G>}255qY
//负责部分文件的抓取 .`H5cuF`
**FileSplitterFetch.java 2@],ZLa
*/ *:7rdzn
package NetFox; h7oo7AP
!9e=_mY
^[`%&uj!g
import java.io.*; V=l0(03j~
import java.net.*; [|$h*YK
_N cR)2
Ll't>)
public class FileSplitterFetch extends Thread { 2l'6.
nR~@#P\
oZgjQM$YP
String sURL; //File URL O0v}43J[
long nStartPos; //File Snippet Start Position >]TWXmx/w
long nEndPos; //File Snippet End Position qe#tj/aZ
int nThreadID; //Thread's ID ~ .g@hS8>
boolean bDownOver = false; //Downing is over ;$|nrwhy
boolean bStop = false; //Stop identical 6d}lw6L
FileAccessI fileAccessI = null; //File Access interface Bsvr?|L\
q3!bky\
JH9J5%sp
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZMlm)?m
{ !Ai@$tl[S
this.sURL = sURL; (w3YvG.
this.nStartPos = nStart; $s:aW^k
this.nEndPos = nEnd; v\ )W?i*l
nThreadID = id; C&%_a~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [z{1*Xc
} Wac&b
_B<X`L =
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public void run() 6bC3O4Rw
{ F$]Pk|,
while(nStartPos < nEndPos && !bStop) S,UDezxg
{ ?:q*(EC<
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try{ ~$^XP.a.
URL url = new URL(sURL); &h/Xku&0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3=j"=-=
httpConnection.setRequestProperty("User-Agent","NetFox"); DvvK^+-~
String sProperty = "bytes="+nStartPos+"-"; /U9"wvg
httpConnection.setRequestProperty("RANGE",sProperty); 46h<,na?,
Utility.log(sProperty); ;e*!S}C,
m{HS0l'
zrb}_
InputStream input = httpConnection.getInputStream(); Iefn$
//logResponseHead(httpConnection); (jE9XxQY
?e 4/p
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byte[] b = new byte[1024]; 4V`G,W4^J
int nRead; FZnw0tMq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j#ab_3xH
{ > ~O.@|
nStartPos += fileAccessI.write(b,0,nRead); NgPk&niM
//if(nThreadID == 1) gPPkT"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zO6oT1I
} lThB2/tV\
6'f;-2
SmO~,2=
Utility.log("Thread " + nThreadID + " is over!"); 0g8NHkM:2a
bDownOver = true; %pCTN P
//nPos = fileAccessI.write (b,0,nRead); +ZP7{%
} R:qW;n%AF
catch(Exception e){e.printStackTrace ();} ECmW`#Otb)
} w7L)'9
} 8}:nGK|kx
|[8Th4*n
Ny/MJ#Lq
//打印回应的头信息 VIf.q)_k
public void logResponseHead(HttpURLConnection con) t]G:L}AOl
{ JBZ@'8eqi]
for(int i=1;;i++) -KbYOb
{ ns4,@C$
String header=con.getHeaderFieldKey(i); Ow,b^|
if(header!=null) HGg@ _9tW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #/37V2E
Utility.log(header+" : "+con.getHeaderField(header)); ,V}WM%Km
else |_U= z;Y
break; Tlr v={
} )+Pus~w
} lp8v0e4
fc>L K7M
#g!.T g'
public void splitterStop() F:DrX_O%
{ hi[pVk~B)
bStop = true; q5S9C%b
} aw>#P
I%Z
<gBA1oRz
} BJ(M2|VH
|4`{]2C
w4Z'K&d=
/* 1h5 Akq
**FileAccess.java 32 =z)]FZ
*//文件访问(定位，写) e96k{C`j0
package NetFox; |ENh)M8}r
import java.io.*; }ad|g6i`
jc9y<{~x/
.N(p=9
public class FileAccessI implements Serializable{ |Q>IrT
*{{89E>wC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tLmTjX .6
RandomAccessFile oSavedFile; Y <qm{e
long nPos; 3+bt~J0
Rlirs-WQ
?z u8)U
public FileAccessI() throws IOException KK &?gTa
{ I<tm"?q0
this("",0); @=kSo -SX
} J$v?T$LVw
PFK '$
CJI~_3+K
public FileAccessI(String sName,long nPos) throws IOException B7vpsSL
{ Q NVa?'0"Y
oSavedFile = new RandomAccessFile(sName,"rw"); )\^-2[;
this.nPos = nPos; ^Zp>G{QL{
oSavedFile.seek(nPos); *uvQ\.
} _<2E"PrT
:eLVC7'
29q _BR *:
public synchronized int write(byte[] b,int nStart,int nLen) E1f\%!2l
{ C"enpc_C/
int n = -1; 01o4Th m
try{ tklH@'q
oSavedFile.write(b,nStart,nLen); WOf 4o
n = nLen; Xb,3Dvf
} 61 ~upQaR
catch(IOException e) {kAc(
{ 2)~> R
e.printStackTrace (); 5rUdv}.
} =E{`^IT'R
T9q-,w/j;
;ovP$ vl>
return n; #LN`X8Wz'
} ^y4Z+Gu[
kz7(Z'pw
-s'-eQF J
} w)jISu;RG
!$>R j
9JKEw
/* @$K"o7+]
**SiteInfoBean.java cPc</[x[W
*/ B48={
package NetFox; ~.lPEA %%
h3@v+Z<}
!FFU=f
public class SiteInfoBean { B^jc3 VsR
FN) $0
BJo*'US-Q
private String sSiteURL; //Site's URL R_S.tT!
private String sFilePath; //Saved File's Path -;k+GrLr^
private String sFileName; //Saved File's Name 63x?MY6
private int nSplitter; //Count of Splited Downloading File Xm2z}X(%
u08mqEa
>~+ELVB&
public SiteInfoBean() 8|58 H
{//nSplitter的缺省值为5 VTHH&$ZNq
//default value of nSplitter is 5 g95`.V}
this("","","",5); U_c*6CK
} IRqy%@)
KRKCD4
i8HTzv"J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "`1bA"E
{ # c^z&0B}
sSiteURL= sURL; 2Q:+_v
sFilePath = sPath; c_!cv":s
sFileName = sName; ^@NU}S):yN
this.nSplitter = nSpiltter; g5r(>,vY
_ZkI)o
.y:U&Rw4
} q?/a~a
,L'zRyP
w$-6-rE]d
public String getSSiteURL() W-lN>]5}m
{ (7=9++uU
return sSiteURL; Aj]V`B:65
} Jo23P.#<
<0q;NrvUb
Bo%NFB;
public void setSSiteURL(String value) *$ %a:q1U
{ U}j0D2
sSiteURL = value; qPfQy
} mUF,@>o
hODWB&b
/FEVmH?
public String getSFilePath() pBA7,z"`mP
{ @/-\k*T
return sFilePath; 5(HG|
} t |A-9^t'!
'$zIbQ:
R`^_(yn>
public void setSFilePath(String value) J!U}iD@occ
{ {o`]I>gb
sFilePath = value; p|D/;Mk
} w!clI8v/
:'*~uJrR
cJ @Wt>YI
public String getSFileName() j9+w#G]hV
{ 54li^
return sFileName; <1\Nb{5
} :T !'N\7
aM0f/"-_
ur7q [n
public void setSFileName(String value) zi*R`;_`,
{ 2u*KM`fa`
sFileName = value; 2Ny"O.0h
} _&ks1cw
m<"WDU?y;
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public int getNSplitter() *CTlOy
{ ` 3K)GA
return nSplitter; 2Gaa(rJ5o
} u-G+ j)
pYZ6e_j1~
5>N2:9We
public void setNSplitter(int nCount) G..aiA
{ :mn>0jK,N
nSplitter = nCount; _#8RSr8'y
} ls:w8&`*
} b-Q>({=i
74k dsgQf
o@i#|kx,
/* mg.kr:
**Utility.java Z+. '>
*/ 4s{~r
package NetFox; .j<]mUY
"J8vjr1/
!sW(wAy?o
public class Utility { 7f!YoW;1
A='N=^Pm
WQL\y3f5
public Utility() `gf0l /d
{ % *INT
)@Yf]qx+Y<
[dIXR
} bU:EqW\(^
=sJ7=39
//线程睡眠 6'G6<8>-
public static void sleep(int nSecond) 22M1j5
{ 8sM|%<$=j
try{ v)t:|Q{I
Thread.sleep(nSecond); q[W 0 N>
} r@t9Ci=}
catch(Exception e) _Wq
{ "ZsOd>[/
e.printStackTrace (); WRyaKM
} N&g3t%F
} qr4pR-Gdr
mA+&Io
//日志 J1I ;Jgql(
public static void log(String sMsg) a>]uU*Xm
{ ?Unb? {,&2
System.err.println(sMsg); v|%Z+w
} kG@@ot" n
b#toM';T
2ZMb<b4H
public static void log(int sMsg) B!_mC<*4`X
{ #W'HR
System.err.println(sMsg); 2s&*
} (@<c6WS
} wKYZa# u
JedmaY06=
MVTMwwO\[
/* &d+Kg0:
**TestMethod.java : $Y9jR
*/ $M lW4&a|
package NetFox; dzsmIV+
kabnVVn~
=2zJ3&9
public class TestMethod { 6[LM_eP
ceM6{N<_U
,5kKimTt
public TestMethod() =;3Sx::=
{ ///xx/weblogic60b2_win.exe + SFVv_n
try{ k*E\B@W>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c5l.B#-lY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EB=-H#
SiteFileFetch fileFetch = new SiteFileFetch(bean); `U)hjQ~pP
fileFetch.start(); Co9QW/'i
} 9{}1r2xW
catch(Exception e){e.printStackTrace ();} E4W -hq~
p|jV{P
OjF_ %5
} V9(@Y
wztA3ZL*W1
Mjfx~I27
public static void main(String[] args) :x{NBvUIc
{ Q`D~5ci
new TestMethod(); C>$E%=h+_
} , GY h9
} .0iQad&duh
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