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)); V%X:1 8j
} T#MA#H2
for(int i=0;i<nEndPos.length-1;i++) \O8Y3|<
{ v_?s1+w
nEndPos = nStartPos[i+1]; d~togTs1
} :t2 9`x
nEndPos[nEndPos.length-1] = nFileLength; t(Q&H!~e
} d,GtH)(s
} bLU^1S8Z
z5|e\Z
UFzM#
//启动子线程 FgFJ0fo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &cv@Kihq(
for(int i=0;i<nStartPos.length;i++) \Owful
{ fPh}l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q1O_CC}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zIAu3
nStartPos,nEndPos,i); BR&Qw'O%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +d6Aw}*
fileSplitterFetch.start(); 7G<KrKal
} ~x4{P;y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4~MJ4:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7/p J6>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %2rHvF=
nEndPos = " + nFileLength); .-O@UQx.I
// fileSplitterFetch[nPos.length-1].start(); Q`@$j,v
?$)x$nS`
K$37}S5
//等待子线程结束 QoT3;<r}
//int count = 0; h a,=LV
//是否结束while循环 B"?+5A7
boolean breakWhile = false; ]<\;d B
z^a6%N
\GbHS*\+
while(!bStop) Q}=W>|aE.
{ s{1Deek=
write_nPos(); @aqd'O
Utility.sleep(500); |5<&r]xN
breakWhile = true; He0N
HX /GLnY/X
m>*A0&??[
for(int i=0;i<nStartPos.length;i++) 8XS{6<
{ {LB }v;?l
if(!fileSplitterFetch.bDownOver) c5wkzY h
{ &k_wqV
breakWhile = false; @LWxz
break; R[>;_}5">
} t=E|RYC(k
} quCWc2pXX
if(breakWhile) zT4ulXN
break; TsFdy{/o*
*Sz{DE1U
guUr1Ij
//count++; ~J. Fl[
//if(count>4) "z#?OV5
// siteStop(); v]`A_)[
} |U#w?eE=
fa+W9
bWQORjnd8
System.err.println("文件下载结束！"); $)TF,-#x
} Kt4\&l-De
catch(Exception e){e.printStackTrace ();} 4xAlaOw5M
} CtC`:!Q
"k6IV&0 3x
c~L6fvS
//获得文件长度 !6tC[W`
public long getFileSize() 4_m /_Z0x
{ Hdq/E>u
int nFileLength = -1; vN%j-'D\A4
try{ d*\C^:Z
URL url = new URL(siteInfoBean.getSSiteURL()); Nh\8+v*+{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :oj) eS[Y
httpConnection.setRequestProperty("User-Agent","NetFox"); jC Kt;lj
ndCS<ojcBP
oRbYna?J
int responseCode=httpConnection.getResponseCode(); iQ]c k-
if(responseCode>=400) P15*VPy
{ g7U:A0Z
processErrorCode(responseCode); +/>YH-P=
return -2; //-2 represent access is error Y"/UYxCm|&
} mN'9|`>V>
a]wcA
|nH0~P#!
String sHeader; <<2b2?aS`
mQA<t)1
<9k}CXv2PK
for(int i=1;;i++) J,=E5T}U^
{ Obc3^pV&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >'|xQjLl
//Utility.log(in.readLine()); bq6{ty"
sHeader=httpConnection.getHeaderFieldKey(i); K!: ,l
if(sHeader!=null) sBXk$
{ -L'K
if(sHeader.equals("Content-Length")) / ?[gB:s
{ "xc*A&Sg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WJSHLy<a
break; e$^!~+J7
} wY ;8UN
} PKM$*_LcGI
else +@)$l+kk9
break; OO wA{]gK
} z3jzpmz
} Lr\ B
catch(IOException e){e.printStackTrace ();} :kx#];2i
catch(Exception e){e.printStackTrace ();} *-!ndbf
IK?$!jh
4"X>_Nt6
Utility.log(nFileLength); GN;XB b]w
rnhf(K.{3
~\}EROb<
return nFileLength; 'MQGR@*
} 0?Wf\7
}~CZqIP
taEMr> /
//保存下载信息（文件指针位置） dVt@D&
private void write_nPos() JHZo:Ad -&
{ kJeOlO[
try{ -*q2Y^A^l
output = new DataOutputStream(new FileOutputStream(tmpFile)); Qn3+bF4
output.writeInt(nStartPos.length); }0nB'0|y
for(int i=0;i<nStartPos.length;i++) 3L]^x9Cu)
{ D&m"~wI
// output.writeLong(nPos); 4$2T zJE
output.writeLong(fileSplitterFetch.nStartPos); nN\XVGP,t
output.writeLong(fileSplitterFetch.nEndPos); [}>6n72gNh
} %1 ^jd\
output.close(); /"{ ,m!
} [=1?CD
catch(IOException e){e.printStackTrace ();} {=4:Tgw
catch(Exception e){e.printStackTrace ();} +<WT$ddK=5
} PW<wjf,rQ
p2vUt
P]x+Q
//读取保存的下载信息（文件指针位置） OjEA;;qq
private void read_nPos() UnF4RF:A2&
{ _NnOmwK7
try{ _rJSkZO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ru aJ9O
int nCount = input.readInt(); $K fk=@
nStartPos = new long[nCount]; BvR3Oi@Wc
nEndPos = new long[nCount]; |3@Pt>Ikl
for(int i=0;i<nStartPos.length;i++) oP75|p
{ G&3<rT3Ib
nStartPos = input.readLong(); ;l?(VqX_E
nEndPos = input.readLong(); XRz6Yf(/
} J5IJy3d
input.close(); 13kb~'+&r
} 0U*"OSpF
catch(IOException e){e.printStackTrace ();} )9Ojvp=#r:
catch(Exception e){e.printStackTrace ();} ]LOtwY
} 8HA=O?Cg
B:.;:AEbT
ZSt ww{Z
private void processErrorCode(int nErrorCode) $*-L8An?
{ ve^MqW&S
System.err.println("Error Code : " + nErrorCode); G_mu7w
} =V 7w CW
CWYJ<27v{
.WE0T|qDX
//停止文件下载 d`7] reh
public void siteStop() 5c7a\J9>
{ C$gLi8|m
bStop = true; K(<P" g(
for(int i=0;i<nStartPos.length;i++) @cGql=t
fileSplitterFetch.splitterStop(); rNC3h"i\
L"/ato
?EAqv]
} FQ)Ekss~C
} c?",kzo
//负责部分文件的抓取 }!Lr!eALr
**FileSplitterFetch.java hDMp^^$
*/ ksp':2d}
package NetFox; 4]KceE
?%ntO]
oP 0j>i,"&
import java.io.*; ,[#f}|s_
import java.net.*; ~A4WuA
7SZs/wWh%
?0Zw ^a
public class FileSplitterFetch extends Thread { ^]gl#&"D
Z Uv_u6aD
=^vUb
String sURL; //File URL t%@pyK
long nStartPos; //File Snippet Start Position =x>k:l~s
long nEndPos; //File Snippet End Position LJ3UB
int nThreadID; //Thread's ID -wRzMT19MG
boolean bDownOver = false; //Downing is over q'tT)IgD
boolean bStop = false; //Stop identical bxq`E!]
FileAccessI fileAccessI = null; //File Access interface $*R9LPpk+
8w'8n
e: tp7w 4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +i =78
{ hd-ds~ve
this.sURL = sURL; W9~datIh>
this.nStartPos = nStart; (eP)>G]
this.nEndPos = nEnd; $h9!"f[|j
nThreadID = id; -bF+uCfba
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dM$S|,H
} _P:P5H8
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public void run() qFk(UazN
{ 04t_
while(nStartPos < nEndPos && !bStop) Nfh(2gK+
{ l ,.;dw
(%Rs&/vU~
(k~c]N)v
try{ J4i0+u
URL url = new URL(sURL); QR)eJ5<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u 6+
httpConnection.setRequestProperty("User-Agent","NetFox"); T9A5L"-6T
String sProperty = "bytes="+nStartPos+"-"; VrK5a9*^
httpConnection.setRequestProperty("RANGE",sProperty); I_rVeMw=
Utility.log(sProperty); x&d<IU)5
S0`*
{PKER$C
InputStream input = httpConnection.getInputStream(); q8J/tw?%v
//logResponseHead(httpConnection); %O${EN
@[Th{HTc.G
`g~-5Z~J
byte[] b = new byte[1024]; mqL+W
int nRead; vY6|V$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lnzhs;7L
{ `*a,8M%
nStartPos += fileAccessI.write(b,0,nRead); *QX$Mo^E
//if(nThreadID == 1) C0M{zGT>}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >+r2I%
} va0 a4s1O
;b^@o,=
7o<RvM
Utility.log("Thread " + nThreadID + " is over!"); ^&}Y>O,
bDownOver = true; >Vvc55z
//nPos = fileAccessI.write (b,0,nRead); ;g9+*$Gw
} oaHBz_pg
catch(Exception e){e.printStackTrace ();} -vyC,A
} -Da_#_F
} \3l;PY
3-05y!vbcE
[,dsVd
//打印回应的头信息 ?2M15Q
public void logResponseHead(HttpURLConnection con) b+3pu\w`
{ MAXdgL[]
for(int i=1;;i++) M@8(h=
{ #L"h>,b
String header=con.getHeaderFieldKey(i); MI/1uw
if(header!=null) wv<"W@& 9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i[<O@Rb
Utility.log(header+" : "+con.getHeaderField(header)); .f}I$ "2
else SG~R!kN}Q
break; 0ode&dB
} eg3{sDv,
} 1#'wR3[+
p7*\]HyE)
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public void splitterStop() Q~9:}_@
{ A1|:$tED+2
bStop = true; Kl*##qw!
} aU3&=aN+
&(K*TB|Om
7(jt:V6V
} +,smjg:O
~"-wSAm
Z5+0?X0i
/* 6ul34\;
**FileAccess.java th]9@7UE,
*//文件访问(定位，写) Ei#"r\q j_
package NetFox; kxKBI{L
import java.io.*; p\(%bO
Q/< $ (Y
QoqdPk#1
public class FileAccessI implements Serializable{ X\h]N
?Z;knX\?J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .G^.kg ,
RandomAccessFile oSavedFile; <'/+E4m
long nPos; Dr;@)
IlwY5iL
^,?]]=mE
public FileAccessI() throws IOException Tj>~#~
{ 5!?><{k=%
this("",0); )q#b^( v
} 0s4%22
BqR8%F
yXDf;`J
public FileAccessI(String sName,long nPos) throws IOException m86w{b$8
{ PPohpdd)
oSavedFile = new RandomAccessFile(sName,"rw"); bJ9>,,D
this.nPos = nPos; gP<l
oSavedFile.seek(nPos); 8zr)oQ:
} fx9c1h9s
)2\6Fy0S
-PxA~((g5
public synchronized int write(byte[] b,int nStart,int nLen) `/#6k>
{ #w#B'
int n = -1; s7=]!7QGS!
try{ *F&C`]
oSavedFile.write(b,nStart,nLen); Z,ag5 w`]L
n = nLen; x3)qK6,\
} Jln dypE
catch(IOException e) P E.^!j
{ aWW|.#L
e.printStackTrace (); 6N6d[t"
} ]_j{b)t
Cvq2UNz(R
eja_+`cJ
return n; >`u} G1T\
} I lvjS^j
Zs)HzOP)9
/)6<`S(
} s&z+j%;+o
p)d'yj
Fn$EP:>
/* YWjw`,EA(
**SiteInfoBean.java mM1\s>o
*/ Id|38
package NetFox; 7zT]\AnO
PWx2<t<;9
#%Uk}5;-
public class SiteInfoBean { ?< mSEgvu
wSnY;Z9W_
-@e9!/GP,
private String sSiteURL; //Site's URL ,J~kwJ$L
private String sFilePath; //Saved File's Path u:NSPAD)
private String sFileName; //Saved File's Name 6O!&!
private int nSplitter; //Count of Splited Downloading File 2t*@P"e!
:J5xO%WA(
PL[7|_%
public SiteInfoBean() SX$v&L<
{//nSplitter的缺省值为5 PJsiT4<
//default value of nSplitter is 5 bwS1YGb
this("","","",5); Zw`Xg@;xP
} H~e;S#3_v
xm6cn\e
`c ^2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?`3`azfM
{ Ir}r98lz
sSiteURL= sURL; z;x$tO
sFilePath = sPath; 4&2aJ_ 2y
sFileName = sName; YcBY[i0
this.nSplitter = nSpiltter; ]2+7?QL,
S9U,so?
,nD:W
} 5^~%10=
2xN1=ug
LkD$\i
public String getSSiteURL() TXWi5f[
{ 9#IKb:9k
return sSiteURL; |<t"O
} g@BQ!}_#5
@2yi%_]h
G'{$$+U^K
public void setSSiteURL(String value) _=Ed>2M)no
{ ggR@& \
sSiteURL = value; s_}T-%\
} }SR}ET&z
hiZE8?0+~N
tIR"y:U+
public String getSFilePath() %6}S1fuA
{ /f@VRME
return sFilePath; id="\12Bw
} {f3&s4xj=
dh#4/Wa,
Av:5v3%
public void setSFilePath(String value) YKk?BQ"
{ NHG+l)y:
sFilePath = value; ![YLY&}s
} - |n\
<2Lcy&w_M
&^KmfT5C
public String getSFileName() Mn7nS:
{ ;gfY_MXnF
return sFileName; #-?pY"N,
} }JyWy_Y
^_BHgbS%;
WlVp|s{TYP
public void setSFileName(String value) %y;E1pva
{ C50&SrnBU1
sFileName = value; E#?*6/
} +`4`OVE_#
Q|/uL`_ni
}GX[N\$N
public int getNSplitter() ihivJZ
{ <+ 0cQq=2
return nSplitter; T7`9[
} 'wB6-
^{\gD23
O]rAo
public void setNSplitter(int nCount) AW3\>WC
{ <>\s#Jf/
nSplitter = nCount; aVsA5t\zi
} {?tK]g#
} A;VjMfoB
E=!=4"rZF
_q*4+x
/* 0ant0<
**Utility.java NMq#D$T
*/ C%P)_)--V
package NetFox; h#a;(F4_7
gx+bKGB`
wBlfQ w-N
public class Utility { :.KN;+tP
v"'Co6fw
oL?(; `"&
public Utility() >'IFr9&3
{ "[(&$I
<s/n8#i=H
A$*#n8,
} ).aQ}Gwx^
9$[I~I#z
//线程睡眠 fh~"A`d
public static void sleep(int nSecond) 5)X;q-
{ .Cv0Ze
try{ K"~Tk`[0Q
Thread.sleep(nSecond); J[E_n;d1
} fBCW/<Z
catch(Exception e) jtqH3xfy
{ 4.]xK2sW
e.printStackTrace (); e.pm`%5bO
} 1,cd[^`.
} 9=,^^,q
b~F(2[o
//日志 aq-`Bar
public static void log(String sMsg) @\-i3EhR
{ 5f+ziiZ
System.err.println(sMsg); z@!zQ Vp
} 4o,%}bo&
3w&fN3 1
$@m)8T
public static void log(int sMsg) w)x`zVwO
{ _@es9
System.err.println(sMsg); kOfq6[JC
} cd8ZZ8L
} mNcoR^(VN
X4<!E#
J?/.|Y]e
/* p^^Ai
**TestMethod.java Jvi"K
*/ k+k&}8e
package NetFox; a'R)3:S
$lkd9r1
qGndh
public class TestMethod { xEK+NKTeV
">b~k;M?
}@IRReQ
public TestMethod() oZvQ/|:p!
{ ///xx/weblogic60b2_win.exe RG(m:N
try{ nnBgTtsC]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "BB#[@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e@k`C{{C]o
SiteFileFetch fileFetch = new SiteFileFetch(bean); <:#O*Y{
fileFetch.start(); xl5n(~g)p
} e'<pw^I\
catch(Exception e){e.printStackTrace ();} f'/@h Na3
,#^<0u+zrF
%qA +zPf
} mT N6-V
XQEGMaZ
KMz\h2X
public static void main(String[] args) 'BT}'qN
{ K GlO;Q~7
new TestMethod(); ?p{xt$<p
} fn|l9k~<O
} yHW=,V.
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