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)); Hco[p+
} M(I 2M
for(int i=0;i<nEndPos.length-1;i++) g2w0#-
{ b@z/6y!
nEndPos = nStartPos[i+1]; hPD2/M
} dhsQfWg#}
nEndPos[nEndPos.length-1] = nFileLength; }3=]1jH6
} ),dXaP[
} R279=sO,J
v\0[B jhL?
W[w8@OCNf
//启动子线程 5A:b \
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1Cp5a2{
for(int i=0;i<nStartPos.length;i++) n\wO[l)
{ to]1QjW-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GC#3{71
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b!ot%uZZ
nStartPos,nEndPos,i); q\[f$==p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >%'|@75K
fileSplitterFetch.start(); ^'6!)y#
} yC6XO&:g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9q;+ Al^Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^hRos
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lUUeM\
nEndPos = " + nFileLength); |4ONGU*`E
// fileSplitterFetch[nPos.length-1].start(); X0Xs"--}
Fl<BCJY
()=
//等待子线程结束 :a[L-lr`e
//int count = 0; r;I3N+
//是否结束while循环 QJ-6aB
boolean breakWhile = false; -HS(<V=a?k
QcIa%lf
K"#np!Y)
while(!bStop) V!a\:%#^Y
{ @/E5$mX`
write_nPos(); YRAWylm
Utility.sleep(500); e>z3\4
breakWhile = true; pDrM8)r
ORyFE:p$
H'&x4[J:
for(int i=0;i<nStartPos.length;i++) >N{K)a
{ rRly0H
if(!fileSplitterFetch.bDownOver) wh[XJ_xY
{ 11Pm lzy
breakWhile = false; mJ)o-BV
break; j%#n}H
} <p-R{}8
} E+]gC
if(breakWhile) ZGH2
break; 7rbl+:y2
^<.mUaP
?8)_,
//count++; m}'kxZTOm
//if(count>4) CAX|[
// siteStop(); CES^ c-. k
} 7=aF-;X3jj
O*`] ]w]
XjuAVNY
System.err.println("文件下载结束！"); 9~SfZ,(
} w|OMT>.
catch(Exception e){e.printStackTrace ();} v\'Eo*4
} Pp*|EW 1
WIa4!\Ky!
\|L ~#{a
//获得文件长度 vxzh|uF
public long getFileSize() TG=) KS
{ `lRZQ:27X
int nFileLength = -1; F%UyFUz
try{ N~=p+Ow[H
URL url = new URL(siteInfoBean.getSSiteURL()); ts<5%{M(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CC;T[b&
httpConnection.setRequestProperty("User-Agent","NetFox"); c0sU1:e0
C1:efa<wV
`$ql>k-6C
int responseCode=httpConnection.getResponseCode(); hl(M0cxEWP
if(responseCode>=400) ' jf$3
{ "W?<BpV~@!
processErrorCode(responseCode); +ng8!k
return -2; //-2 represent access is error {r?O>KDQf(
} jSsbLa@
:,h47'0A
PmZ-H>
String sHeader; K.Nun)<
vUk <z*
5A g4o
for(int i=1;;i++) [y7BHikX)
{ !_3RdS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dq+VW}[EO
//Utility.log(in.readLine()); Z@nWx]iz
sHeader=httpConnection.getHeaderFieldKey(i); ODyK/Q3
if(sHeader!=null) k1e0kxn
{ N,0l5fD~T
if(sHeader.equals("Content-Length")) kAsYh4[
{ f"\G"2C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (j@3=-%6G
break; 0 XxU1w8\V
} s"7wG!yf
} w] i&N1i
else 56Z 1jN^U
break; B[%FZm$`M
} h:\WW;s[B
} dO =fbmK
catch(IOException e){e.printStackTrace ();} u[5*RTE
catch(Exception e){e.printStackTrace ();} TcPYDAa
5V;BimI
b_+dNoB
Utility.log(nFileLength); 9*pH[vH
3J%(2}{y
;m`k#J?
return nFileLength; uH!uSB2
} JKN0:/t7Q
klmRU@D
vPz$jeA
//保存下载信息（文件指针位置） xdGmiHN
private void write_nPos() A\nL(Nd
{ ;.>CDt-E]
try{ $$ma1.t"
output = new DataOutputStream(new FileOutputStream(tmpFile)); ca%s$' d
output.writeInt(nStartPos.length); #usi1UWB#Q
for(int i=0;i<nStartPos.length;i++) :y^0]In
{ 'id]<<F
// output.writeLong(nPos); puEuv6F
output.writeLong(fileSplitterFetch.nStartPos); iOXxxP%#
output.writeLong(fileSplitterFetch.nEndPos); *{5p/}p
} iPgewjx
output.close(); 29p`G1n
} \wwY?lOe
catch(IOException e){e.printStackTrace ();} Q}zAC2@L
catch(Exception e){e.printStackTrace ();} /UtCJMQ
} Sqw:U|h\FS
2Hl0besm
I-<U u2
//读取保存的下载信息（文件指针位置） TJjcX?:(
private void read_nPos() :)hS-*P
{ VUAW/
try{ 8@y@}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }QrBN:a$(
int nCount = input.readInt(); gx,BF#8}
nStartPos = new long[nCount]; g$$i WC!S<
nEndPos = new long[nCount]; {8`V5:
for(int i=0;i<nStartPos.length;i++) D_mdX9-~
{ U-!+Cxjs
nStartPos = input.readLong(); Zt;3HY=y
nEndPos = input.readLong(); l-4+{6lz
} fP<Tvf
input.close(); iG*@(
} G>"=Af(t?Y
catch(IOException e){e.printStackTrace ();} ?XOl>IO
catch(Exception e){e.printStackTrace ();} 0*G =~:
} 6?GR+;/
|e49F
u By[x 0
private void processErrorCode(int nErrorCode) =qG%h5]n
{ cXP*?N4Cf
System.err.println("Error Code : " + nErrorCode); t6m&+N
} {6}H}_(]
\o}m]v i
Z{&dzc
//停止文件下载 vw(X9xa
public void siteStop() tgeX~.
{ !Q(xA,p
bStop = true; j8gw]V/B:
for(int i=0;i<nStartPos.length;i++) +$_.${uwV
fileSplitterFetch.splitterStop(); Y.FqWJP=p
n~`1KC4
KA^r,Iw
} phkfPvL{
} Am>^{qh9
//负责部分文件的抓取 ;J<K/YdI
**FileSplitterFetch.java 4I&e_b< 30
*/ .%Pt[VQ
package NetFox; l}\q }7\)
&USKudXmb
]nmVT~lBe"
import java.io.*; =Rv!c+?
import java.net.*; N`o[iHUj \
V+04X"
{DfXn1Cg0U
public class FileSplitterFetch extends Thread { FZdZGK
pCOtk'n
{k:W?`
String sURL; //File URL W_JFe(=3,
long nStartPos; //File Snippet Start Position rt +a/:4+
long nEndPos; //File Snippet End Position z#DgoA
int nThreadID; //Thread's ID E(%_aFx>/
boolean bDownOver = false; //Downing is over 9:[L WT&
boolean bStop = false; //Stop identical j_w"HiNBA
FileAccessI fileAccessI = null; //File Access interface i6Zsn#Z7)
_d<xxF^q
kF,_o/Jc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Cf&.hod
{ v2ab
this.sURL = sURL; QY)hMo=|o8
this.nStartPos = nStart; Wycood*
this.nEndPos = nEnd; Nj~3FL
nThreadID = id; ePD~SO9*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '+8`3['
} >v\t> [9t
g$CWGB*%lm
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public void run() )7`2FLG
{ a8Va3Y
while(nStartPos < nEndPos && !bStop) o'#ow(X
{ x~;1CB
eW"L")
O%hmGW4
try{ Ej;BI#gx=
URL url = new URL(sURL); on0MhW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r0xmDJ@y
httpConnection.setRequestProperty("User-Agent","NetFox"); ]; CTr0
String sProperty = "bytes="+nStartPos+"-"; C~o\Q#*j
httpConnection.setRequestProperty("RANGE",sProperty); 6 +2M$3_U
Utility.log(sProperty); JJE3\
T ?HG}(2
j*7#1<T
InputStream input = httpConnection.getInputStream(); -9f+O^x
//logResponseHead(httpConnection); lPBWpHX
4ju=5D];
7~f"8\
byte[] b = new byte[1024]; C*C;n4AT
int nRead; JI5%fU%O#n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k/lU]~PE
{ [v%j?
nStartPos += fileAccessI.write(b,0,nRead); ZYMacTeJjg
//if(nThreadID == 1) D~^P}_e.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k1h>8z.Tg
} 5w^6bw){
~R+,4
@,\J\ rb
Utility.log("Thread " + nThreadID + " is over!"); C2a2K={
bDownOver = true; O_S%PX
//nPos = fileAccessI.write (b,0,nRead); g##yR/L
} QT<\E`v
catch(Exception e){e.printStackTrace ();} (p?7-~6|:
} 3_ P<0%
} Yvn*evO4
R?Ou=p .
>@ :m#d
//打印回应的头信息 !yQ%^g`
public void logResponseHead(HttpURLConnection con) {0Jpf[.f
{ J? 4E Hl
for(int i=1;;i++) ^T< HD
{ UgP
String header=con.getHeaderFieldKey(i); P/ XO5`
if(header!=null) k x?m "a%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fvNj5Vq:
Utility.log(header+" : "+con.getHeaderField(header)); #`5>XfbmQ(
else Z;"YUu[(
break; 7]}2`^9
} )?$zY5
} Q&?^eOI&#(
N~)RR {$w
Kt*kARN?
public void splitterStop() N'@E^ rYc
{ 6Qx[W>I
bStop = true; {k15!(:i~a
} cAQ_/>
h(4&!x
$p)e.ZMgE
} \;FE@
hf1h*x^J
N2Qb+
/* :RG=3T[
**FileAccess.java ']__V[
*//文件访问(定位，写) o+%($p
package NetFox; tVr^1Y
import java.io.*; \jCN ]A<
JE=3V^k
"">{8
public class FileAccessI implements Serializable{ >V$ S\"
o ?`LZd:{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $a.,;:
RandomAccessFile oSavedFile; %s),4
long nPos; Id<O/C
k"pN
*a2-Vte
public FileAccessI() throws IOException k+%c8w 9
{ gnWEsA\!
this("",0); G]k+0&X
} 6Z>G%yK
`Re{j{~s
*Me&>"N"
public FileAccessI(String sName,long nPos) throws IOException HU47S
{ (p!w`MSv
oSavedFile = new RandomAccessFile(sName,"rw"); ypy
this.nPos = nPos; =}OcMM`f
oSavedFile.seek(nPos); `7$Sga6M
} h}n?4B~Gi
["~T)d'
8}.V[,]6
public synchronized int write(byte[] b,int nStart,int nLen) (/e[n.T
{ *Kmo1>^
int n = -1; |FP@NUX\
try{ Cb i;CF\{
oSavedFile.write(b,nStart,nLen); k*e$_
n = nLen; ]uZaj?%J<
} Dk#4^`qp1
catch(IOException e) pdq5EUdS
{ SpA-E/el
e.printStackTrace (); .:9XpKbt
} *Q!I^]CR
qL2Sv(A Z!
yP*oRV%uX
return n; HvJ-P#
} B{2WvPX~q
eEZZ0NNe;
{D`_q|
} s#4Q?<65u
%j. *YvveW
#QM9!k@9k
/* =j^wa')
**SiteInfoBean.java rL23^}+^`
*/ `-yiVUp1:z
package NetFox; W+'f|J=
0kxe5*-|
iM +p{/bN
public class SiteInfoBean { K[R.B!;N
.gs:.X)TG9
R&@NFin
private String sSiteURL; //Site's URL 8!|LJI
private String sFilePath; //Saved File's Path !D~\uW1b
private String sFileName; //Saved File's Name /" 6Gh'
private int nSplitter; //Count of Splited Downloading File Nf1&UgX
' )~G2Ys
jm&PGZ#n=R
public SiteInfoBean() J5L[)Gd)D
{//nSplitter的缺省值为5 aBT8mK -.
//default value of nSplitter is 5 0RGqpJxk
this("","","",5); CQh6;[\:
} |TRl>1rv
ur JR[$p
VX,@Gp_'m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ur,{ZGm
{ "VI2--%v3
sSiteURL= sURL; (Nn)_caVb
sFilePath = sPath; w|( ix;pK
sFileName = sName; miEf<<L#z
this.nSplitter = nSpiltter; (&oT6Ji
Hq0O!Zv
ey ?paT
} 1(vcM
iL;{]A'0
t`G<}t
public String getSSiteURL() sHm:G_
{ PmlQW!gfBi
return sSiteURL; 6T-iBJT
} QB6. o6
6(-c$d`C.0
,'a[1RN
public void setSSiteURL(String value) a{+;&j[!
{ ,.TwM;w=
sSiteURL = value; #)z7&nD
} l;vA"b=]
GEZ!z5";BQ
n{E9p3i
public String getSFilePath() =0_((eXwf
{ l(uV@_3
return sFilePath; )@E'yHYO>
} TQsTL2a
Z1sRLkR^
l^;=0UR_
public void setSFilePath(String value) *$9Rb2}kK
{ t&nK5p95(
sFilePath = value; b0h>q$b
} `V=F>s$W
Oi$$vjs2
C`b)}dY
public String getSFileName() gM_MK8py
{ :8l#jU`y
return sFileName; ]:Sb#=,!&!
} g]m}@b6(h
Mk|*=#e;
yCZ[z A
public void setSFileName(String value) Vh8RVFi;c
{ ](SqLTB+?
sFileName = value; 9B2`FJ
} s,]z6L0
+9]CGYj
/A>1TPb09"
public int getNSplitter() sp&g
{ XE?,)8
return nSplitter; ;-d2~1$
} y0\=F
h45RwQ5Z
=`MMB|{6
public void setNSplitter(int nCount) ?Y'r=Q{w
{ LT6VZ,S
nSplitter = nCount; %)PQomn?
} O^<\]_l
} ({9P, D~2
H;Cv]-
k*o>ZpjNH
/* ^s6C']q *O
**Utility.java % QI6`@Y"
*/ N7}yU~j^
package NetFox; 'jjJ[16"d
1j\wvPLr
=801nZJ
public class Utility { HRW}Yl
@+(a{%~7y
:AM_C^j~ D
public Utility() $S2kc$'F
{ GdtR /1
_{48s8V
8e}8@[h
} zZI7p[A[3
nWsR;~pK
//线程睡眠 Vho^a:Z9}W
public static void sleep(int nSecond) ^9 {r2d&c
{ ZY-mUg
try{ _T(MMc
Thread.sleep(nSecond); Z$2Vd`XP
} wZ\% !#}7
catch(Exception e) #u$Z/,
{ A^@,Ha
e.printStackTrace (); VQHQvFRZ)
} GL8 N!,
} (5&l<u"K~
&E$:^a4d
//日志 p^i]{"sjbU
public static void log(String sMsg) *kKdL
{ jWJ/gv~ $
System.err.println(sMsg); XYHVw)
} *&vi3#ur
nQM7@"R
un(fr7NW
public static void log(int sMsg) q($fl7}Y
{ b@yFqgJ_
System.err.println(sMsg); 4!0nM|~
} q.69<Rs
} ?&se]\
KSy.
Eumdv#Qg
/* 5H |<h
**TestMethod.java 9Li.B1j
*/ _~_6qTv-d
package NetFox; 6HxZS+],c
kJ:zMVN
;P2(C >|
public class TestMethod { <]kifiN#
?8aPd"x
jG~UyzWH;
public TestMethod() V'XvwO@
{ ///xx/weblogic60b2_win.exe rBovC
try{ z{dn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9S$?2z".2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W.VyH|?
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3-$w5O3}
fileFetch.start(); HP*AN@>Kw
} ffE&=eh)
catch(Exception e){e.printStackTrace ();} uq_h8JH$
6v9A7g;4.
/dt'iai~l
} e \ rb
@iD5X.c
8et.A
public static void main(String[] args) dI|`"jl#
{ vV+>JM6<K
new TestMethod(); {;j@-=pV
} _=68iDXm
} >Gyg`L\
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