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)); nyw,Fu
} Zo-E0[9
for(int i=0;i<nEndPos.length-1;i++) ^.nvX{H8~=
{ ^ Gq2"rDM
nEndPos = nStartPos[i+1]; jtS+y)2
} gD@ &/j7
nEndPos[nEndPos.length-1] = nFileLength; +r2E5s
} f8lBxK
} HP3~.1Sp
B5 C]4
?0DCjh8We
//启动子线程 #fk)Y1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,B5Ptf#
for(int i=0;i<nStartPos.length;i++) 0{BPT>'
{ ^ B=x-G.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v"F.<Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h<Yn0(.
nStartPos,nEndPos,i); &oWWc$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hm-+1Wx
fileSplitterFetch.start(); B(:Kw;r?
} 6pLB`1[v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), --Dw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PC.$&x4w1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", awHfd5nRS
nEndPos = " + nFileLength); )gmDxD ^C
// fileSplitterFetch[nPos.length-1].start(); fB3O zff
zt[TShD^
l^uP?l"
//等待子线程结束 PJAE~|a
//int count = 0; j<szQ%tJlI
//是否结束while循环 _>dqz(8#
boolean breakWhile = false; &M6)-V4
/raM\EyrlP
= EyxM
while(!bStop) Xd)ba9{
{ 9x;/q7
write_nPos(); PUltn}M
Utility.sleep(500); #Vs/1y`()
breakWhile = true; 3${?!OC
E&{*{u4
`yP-,lA$
for(int i=0;i<nStartPos.length;i++) s|pb0
{ ~XsS00TL`G
if(!fileSplitterFetch.bDownOver) ~BERs;4
{ HAf.LdnzS
breakWhile = false; ![7v_l\Q
break; 6zRJ5uI,/
} Te[[xhTyw
} Uf4QQ`c#
if(breakWhile) "*RCV6{
break; l YH={jJ
6N~ jt
>,@Fz)\:{'
//count++; <j ;HRm
//if(count>4) at,Xad\j
// siteStop(); tPO.^
} nd3]&occ
x^+ C[%
L]K*Do
System.err.println("文件下载结束！"); O.&6J/
} yZ0;\Tr*J
catch(Exception e){e.printStackTrace ();} @ RTQJ+ms
} ~1|sf8
C;dA?Es>R
[cXu<vjFM
//获得文件长度 g_0"T}09(
public long getFileSize() tborRi)
{ X2M<DeF:
int nFileLength = -1; puZ<cV e/
try{ iL|*g3`-f
URL url = new URL(siteInfoBean.getSSiteURL()); l2VO=RDiW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;cp-jY_U
httpConnection.setRequestProperty("User-Agent","NetFox"); O3bK>9<K
`Jm{K*&8Q
4 3]6J]!)
int responseCode=httpConnection.getResponseCode(); :e+GtN?
if(responseCode>=400) e!tgWYN
{ &Eidc .
processErrorCode(responseCode); a(x[+ El
return -2; //-2 represent access is error aCGPtA'
} i$"FUC~'
&\<RVE
B susXW$
String sHeader; o<Y|N
+bdkqdB9
)Bb :tz+
for(int i=1;;i++) k\ I$ve"*
{ "MoV*U2s,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w2+RX-6Ie
//Utility.log(in.readLine()); gvoK
sHeader=httpConnection.getHeaderFieldKey(i); <RGRvv
if(sHeader!=null) hXz"}X n
{ 9?,n+
if(sHeader.equals("Content-Length")) F<V zVEx
{ }Lb];hww1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wv=L_E_
break; ,Yi =s;E
} I=(O,*+PQ
} aj(M{gFq~
else )&_{m K
break; Y] P}7GZ
} -\UzL:9>
} yA%[u.{
catch(IOException e){e.printStackTrace ();} ~@'|R%jJ
catch(Exception e){e.printStackTrace ();} &cpRB&bf
De>pIN;B>
RK rBHqh@
Utility.log(nFileLength); ~RvU+D
e% 5!
l' "<
return nFileLength; Nz!AR$
} f{3FoN=z
,x{5,K.yWq
h(G&X9*
//保存下载信息（文件指针位置） ;A-Ef
private void write_nPos() 6\::Ku4_2
{ 5+ fS$Q
try{ Cs]xs9
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0 |F(qR
output.writeInt(nStartPos.length); ;H:qDBH
for(int i=0;i<nStartPos.length;i++) c#HocwP@
{ 5~rs55W
// output.writeLong(nPos); L {B#x@9tQ
output.writeLong(fileSplitterFetch.nStartPos); L"}@>&6
output.writeLong(fileSplitterFetch.nEndPos); lPFMNRt~8
} /f#rN_4
output.close(); U]R7=
} \2NiI]t]
catch(IOException e){e.printStackTrace ();} E"L'm0i[[
catch(Exception e){e.printStackTrace ();} 0 ?2#SM
} YLFTf1G9
NoKYHN^*w
@kqy!5)K
//读取保存的下载信息（文件指针位置） X='4N<
private void read_nPos() 2ZE4^j|
{ DcOu=Y> 1
try{ OcSLRN?t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IloHU6h'
int nCount = input.readInt(); %H}+'.8
nStartPos = new long[nCount]; q5HHMHB
nEndPos = new long[nCount]; [Xz7.<0#U
for(int i=0;i<nStartPos.length;i++) B"Fg`s+]U
{ -C8awtbC
nStartPos = input.readLong(); G 8NSBaZe
nEndPos = input.readLong(); Pc4sReo'
} )L#I#%
input.close(); 97Q!Rot
} 'fVk1Qj^
catch(IOException e){e.printStackTrace ();} GGLVv)
catch(Exception e){e.printStackTrace ();} UyF]gO
} Eydk645:3
lcUL7
F'*{Fk h
private void processErrorCode(int nErrorCode) ;c;;cJc!
{ 0e}LZ,9e
System.err.println("Error Code : " + nErrorCode); kXOlZC
} D!@c,H
?iia
tGf
//停止文件下载 !MGQ+bD6
public void siteStop() Y.}n,y|J}
{ }NYsKu_cM
bStop = true; #MBYa&Tw7
for(int i=0;i<nStartPos.length;i++) Ql\GL"
fileSplitterFetch.splitterStop(); xknP `T
/\=g;o'
6'Lij&,f?{
} 7M$>'PfO
} Fe/*U4xU
//负责部分文件的抓取 IzL yn
**FileSplitterFetch.java sxuYwQ
*/ J7l1-
package NetFox; ZM)a4h,kcm
0#yo\McZ
~Aq UT]l
import java.io.*; )?_c7 R
import java.net.*; W}Z|v M$
s+(8KYTs`
S&QZ"4jq
public class FileSplitterFetch extends Thread { goxgJOiB
BGA.8qWR4
)P,jpE8
String sURL; //File URL 3-Ti'xM
long nStartPos; //File Snippet Start Position .IYE"0)wJ
long nEndPos; //File Snippet End Position yt<K!=7&
int nThreadID; //Thread's ID ^ 5UIbA(
boolean bDownOver = false; //Downing is over Qb SX'mx<
boolean bStop = false; //Stop identical $:<KG&Br
FileAccessI fileAccessI = null; //File Access interface #=zh&`
U9;AU]A
M<)HJ lr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gGZ$}vX
{ GbMSO
this.sURL = sURL; fo5!d@Nv
this.nStartPos = nStart; ikofJl]9
this.nEndPos = nEnd; jmAWto}.
nThreadID = id; ?5+=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jt;,7Ek
} /O&j1g@
gN(8T_r
\6sp"KqP
public void run() eR;cl$
{ C$?dkmIt
while(nStartPos < nEndPos && !bStop) /gPn2e;
{ ]^.#d
jLZ~9FXF2
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try{ N]5-#
URL url = new URL(sURL); !rwv~9I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0P!6 .-XU
httpConnection.setRequestProperty("User-Agent","NetFox"); QRa>W/N
String sProperty = "bytes="+nStartPos+"-"; g y&B"`
httpConnection.setRequestProperty("RANGE",sProperty); 7 bpV=
Utility.log(sProperty); :.Np7[~{
G-T:7
,!Q2^R
InputStream input = httpConnection.getInputStream(); CM~)\prks
//logResponseHead(httpConnection); B'&%EW]
CjykM])
[S*bN!t
byte[] b = new byte[1024]; d7l0;yR&+
int nRead; jMZ{>l.v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r0hu?3u1?
{ xy[R9_V
nStartPos += fileAccessI.write(b,0,nRead); F7L+bv
//if(nThreadID == 1) 4egq Y0A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); & XcY|y=W
} #:236^xYS
sH#UM(N
_ea!psA0
Utility.log("Thread " + nThreadID + " is over!"); +Pn+&o;D
bDownOver = true; UB=I>
//nPos = fileAccessI.write (b,0,nRead); *R8q)Q
} ?mrG^TV^+r
catch(Exception e){e.printStackTrace ();} /Wk\6
} 5H>[@_u+:
} l*/I ;a$
@@_f''f$
@Vc*JEW
//打印回应的头信息 `|Tr"xavf
public void logResponseHead(HttpURLConnection con) k%JwS_F
{ q]<cn2
for(int i=1;;i++) gNN{WFHQX:
{ @e+QGd;}
String header=con.getHeaderFieldKey(i); p)Z$q2L
if(header!=null) g)2}`}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =3l%ZL/
Utility.log(header+" : "+con.getHeaderField(header)); "M1[@xog
else @/XA*9]l
break; 91e&-acA
} 3fM~R+p
} AEhh 6v
>STWt>s
L)J0TSh
public void splitterStop() E_7N^htv
{ PJS\> N&u
bStop = true; =K}5 fe
} IIs'm!"Y>
WHMt$W}%
dz&8$(f,
} i5q VQo
wjQu3 ,Cj
ojUBa/
/* j:\MrYt0H
**FileAccess.java i\2~yXw\
*//文件访问(定位，写) Z6A*9m
package NetFox; "\)j=MI8u+
import java.io.*; &8z`]mB{t
n<uF9N<
9}jF]P*Q
public class FileAccessI implements Serializable{ >2,x#RQs
+|KnO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ztr,v$
RandomAccessFile oSavedFile; AWc7TW
long nPos; YrL:!\p.
,QdUfM
{-09,Q4[&
public FileAccessI() throws IOException IXe[JL:
{ j"9bt GX
this("",0); uL\ B[<:
} r|:i: ii
U;Y{=07a@
^#9 &Rk!t
public FileAccessI(String sName,long nPos) throws IOException "VRcR
{ \f5$L`
oSavedFile = new RandomAccessFile(sName,"rw"); lqTTTk
this.nPos = nPos; a2SMNC]
oSavedFile.seek(nPos); xJ:15eDC
} >A;Mf*E
CMI%jyiX
JJPU!
public synchronized int write(byte[] b,int nStart,int nLen) ~q5"'
{ c-(,%0G0
int n = -1; T'"aStt6
try{ Np$pz
oSavedFile.write(b,nStart,nLen); odD^xg"L
n = nLen; kG^DHEne
} T;IaVMFG|d
catch(IOException e) x$tx!%,)/S
{ FO&U{(Q
e.printStackTrace (); K?8{y
} rzsb(
[kM)K'-
vT#zc)j
return n; QX1QYwcmG
} ~k'KS 7c
]v{f!r=}
;!v2kVuS]
} R'`q0MoN1
n*D-01vYP
XXBN Nr_CK
/* ^$}9 Enj+Y
**SiteInfoBean.java 6sJN@dFA
*/ : 9wW*Ix
package NetFox; oi^2Pvauh
Y?a*-"
wC+_S*M-K
public class SiteInfoBean { $6kVhE!;
$vlq]6V8
;P3sDN
private String sSiteURL; //Site's URL Ne!F p
private String sFilePath; //Saved File's Path a;WRTV
private String sFileName; //Saved File's Name ms@*JCL!t
private int nSplitter; //Count of Splited Downloading File ^V#9{)B
FAkjFgUJp
Ue^2H[zs-
public SiteInfoBean() RB`Emp&T
{//nSplitter的缺省值为5 GVP"~I~/:
//default value of nSplitter is 5 ]r8t^bqe
this("","","",5); pC2ZN
} [DpGL/Y.
e[.c^Hw
jT}3Zn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A[`c2v-hF
{ ,\laqH\ 1%
sSiteURL= sURL; \x P$m|Y3
sFilePath = sPath; SR7$m<0t*
sFileName = sName; 0*^ J;QGE
this.nSplitter = nSpiltter; i`U:uwW`
C8 9c2
1BO$xq
} ?^t"tY
t{Ck"4Cg
PeT _Ty
public String getSSiteURL() (C>FM8$J
{ 4=!SG4~o
return sSiteURL; yr?*{;
} a+sHW<QeS
AV{3f`
7N9~nEU
public void setSSiteURL(String value) #-*7<wN
{ sLrSi
sSiteURL = value; Z M_ 6A1
} *5?a%p
RZ 4xR
{G$I|<MD2T
public String getSFilePath() zO8`xrN!
{ mO<sw
return sFilePath; wTb7 xBI
} Whp;wAz
41Bp^R}^/
s3@sX_2
public void setSFilePath(String value) t>.1,'zb
{ [!1z; /
sFilePath = value; 29]-s Utqv
} q/w<>u
Ja<pvb
tl9=u-D13@
public String getSFileName() Mwp[?#1j
{ y"q7Gx*^j
return sFileName; ,S[,F0"%
} j}$dYbf$
WwG +Xa
jR-DH]@y
public void setSFileName(String value) &Uq++f6
{ o_;pEe
sFileName = value; J%}9"Q5
} <q|IP_
Q M7z .
AKs=2N>7
public int getNSplitter() C$Pe<C#
{ 2ED^uc: 0S
return nSplitter; gSLwpIK%
} NJK?5{H'
hpp>+=
Xb +)@Y4h
public void setNSplitter(int nCount) b[p<kMTir
{ ;ELQIHnD"
nSplitter = nCount; DwM4/m
} ZfalB
} U U!M/QJ
vQf'lEFk
v\7k
/* s33< }O0
**Utility.java rK&ofc]f$
*/ $jMU|{
package NetFox; eBiP\
EGMj5@>
s!S,;H
public class Utility { $T* ##kyE9
0=Jf93D5
clfi)-^{K
public Utility() F jdh&9Zc
{ $__e7
qZRx,^gd
04-phEA2Q
} uV1H iv-
bDd$79@m
//线程睡眠 bSHlR#!6
public static void sleep(int nSecond) N_S>%Z+
{ :()(P9?
try{ #k? Rl
Thread.sleep(nSecond); N,v4SIC@
} *;A I0
catch(Exception e) Q]X0O10
{ 48,Aq*JFw
e.printStackTrace (); SPKen}g
} ^$3 ~;/|
} ;:xOW$
Y ON@G5^
//日志 mY"DYYR>
public static void log(String sMsg) ]P/eg$u'I
{ xh[4d
System.err.println(sMsg); i(.c<e{v~
} YbZ<=ZzO4
T=7V+
8>q:Q<BB2
public static void log(int sMsg) ]PdpC"
{ Ycb<'M*jE
System.err.println(sMsg); TSu^.K
} 4f,D3e%T|
} ]e+IaZ[Wo
v8g3]MVj3
pJ7wd~wF*
/* B.fLgQK0
**TestMethod.java FxOhF03\=[
*/ Bu?"b=B*
package NetFox; 9R.IYnq
(?-5p;
wqo2iRql
public class TestMethod { 9/C0DDb
j}YZl@dYV
@(.?e<
public TestMethod() (zkh`8L
{ ///xx/weblogic60b2_win.exe A?Jm59{w
try{ QC>I<j&`!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X70vDoW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~h-G
SiteFileFetch fileFetch = new SiteFileFetch(bean); =0xuH>WY}w
fileFetch.start(); b!hxx Z
} 6$wS7Cu
catch(Exception e){e.printStackTrace ();} ko!38BH`/
qS{lay
s%]-Sw9
} z.23i^Q
xXO& -v{
8 g'9( )&
public static void main(String[] args) 2a*1q#MpAt
{ :0ND0A{K:
new TestMethod(); HC w$v#
} jsTb0
} `xe[\Z2
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