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)); E/V_gci
} .8wf {y
for(int i=0;i<nEndPos.length-1;i++) ZJe^MnE (G
{ `^ZhxFX
nEndPos = nStartPos[i+1]; Gg e X
} 9;7Gzr6A"
nEndPos[nEndPos.length-1] = nFileLength; O!!N@Q2g
} '8Cg2v5&w
} =kTHfdin&
v-Tkp Yn
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//启动子线程 3{)!T;Wd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c=,HLHpFO(
for(int i=0;i<nStartPos.length;i++) Al1_\vx7
{ ]ur?i{S,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {p.^E5&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]"/SU6#4:
nStartPos,nEndPos,i); B"YN+So
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nW)?cQ I
fileSplitterFetch.start(); A+|bJ>q
} dGgltY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8WE@ X)e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +T\<oj%}2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,wf:Fr
nEndPos = " + nFileLength); G2<$to~{
// fileSplitterFetch[nPos.length-1].start(); a,36FF~&
IaZmN.k*
L{&>,ww
//等待子线程结束 AJ+\Qs(0
//int count = 0; wBDHhXi0
//是否结束while循环 jG~-V<&
boolean breakWhile = false; :i4AkBNK
0K'{w]Q
2?Y8hm
while(!bStop) $l2`@ia"
{ 9a[1s|>w-
write_nPos(); Qs '_\|/-
Utility.sleep(500); vw 6$v
breakWhile = true; `dw">z,
egK~w8`W%
4E2#krE%
for(int i=0;i<nStartPos.length;i++) (gnN</%
{ Atb`Q'Yrw
if(!fileSplitterFetch.bDownOver) uwQgu!|x
{ 3-btaG'P
breakWhile = false; +`bnQn]x+
break; v%$l(
} ht*N[Pi4;
} _&~l,%)&
if(breakWhile) i=L 86Ks
break; {yv_Ni*6!
A_l\ij$Y
vf zC2
//count++; j,Mbl"P
//if(count>4) [[HCP8Wk
// siteStop(); Zb=;\l*&
} MJh.)kd$
_CPj]m{
cRH(@b Xr
System.err.println("文件下载结束！"); wo+`WnDh
} z .Z
catch(Exception e){e.printStackTrace ();} L pq)TE#
} 43E)ltR=]
o{>4PZ}=g
X1d{7H8A2
//获得文件长度 1d~d1Rd
public long getFileSize() je@&|9h
{ &c 2Qa
int nFileLength = -1; J6[}o4Z
try{ r95,X!
URL url = new URL(siteInfoBean.getSSiteURL()); T ay226
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e/cHH34
httpConnection.setRequestProperty("User-Agent","NetFox"); `+T 2IPN
<o9AjASv\,
$@@ii+W}\
int responseCode=httpConnection.getResponseCode(); k,$/l1D
if(responseCode>=400) |fywqQFq
{ 1$1>cuu
processErrorCode(responseCode); 3b\s;!
return -2; //-2 represent access is error #q K.AZi
} J90:c@O"w
cpl Ny?UIC
Ux1j+}y
String sHeader; -8l(eDm"m
Gk+R,:
sZ~03QvkT
for(int i=1;;i++) |||m5(`S
{ VXiU5n^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _YG@P1
//Utility.log(in.readLine()); )Nqx=ms[(!
sHeader=httpConnection.getHeaderFieldKey(i); %19~9Tw
if(sHeader!=null) |$6Ten[B#
{ ,}\LC;31,
if(sHeader.equals("Content-Length")) ^SsdM#E
{ tH&eKM4G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [<5/s$,i
break; ?FNgJx*\S
} b1>]?.
} k-a1^K3
else A9N8Hav
break; 5k@T{
} g)\Tex<
} Op8Gj `
catch(IOException e){e.printStackTrace ();} b+q'xnA=>
catch(Exception e){e.printStackTrace ();} *^Zt)U1$|
ZnJJ-zP
NC!B-3?x
Utility.log(nFileLength); mhv6.W@
Qy"%%keV'T
jJw
return nFileLength; p[o]ouTcS
} T59FRX
eI:x4K,#
nTc#I~\
//保存下载信息（文件指针位置） -~aG_Bp!($
private void write_nPos() cWyf04-?
{ WMnSkO
try{ W!T[ ^+
output = new DataOutputStream(new FileOutputStream(tmpFile)); s-5#P,Lw
output.writeInt(nStartPos.length); r>! @Z2%s
for(int i=0;i<nStartPos.length;i++) 9(qoME}>=
{ ftcLP
// output.writeLong(nPos); q+4dHS)x
output.writeLong(fileSplitterFetch.nStartPos); 5x|$q kI
output.writeLong(fileSplitterFetch.nEndPos); p#Po?
} Q=d:Yz":S
output.close(); /s%-c!o^
} )X," NJG
catch(IOException e){e.printStackTrace ();} "=K3sk
catch(Exception e){e.printStackTrace ();} Ym"^Ds}
} I L7kpH+y
Du +_dr^4
QHja4/
//读取保存的下载信息（文件指针位置） fd #QCs
private void read_nPos() 'hPW#*#W<
{ g]JRAM
try{ GFE3p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GOGS"q
int nCount = input.readInt(); Tc!n@!RA|
nStartPos = new long[nCount]; *~4<CP+"0
nEndPos = new long[nCount]; ~8UMwpl-
for(int i=0;i<nStartPos.length;i++) KPDJ$,:
{ /2E Q:P
nStartPos = input.readLong(); -O,:~a=*_
nEndPos = input.readLong(); S&-F(#CF^
} H"A@Q.'
input.close(); ~3Pp}eO~V
} <,it<$f#
catch(IOException e){e.printStackTrace ();} = 03G~7B>
catch(Exception e){e.printStackTrace ();} cUP1Uolvn
} o\ce|Dzt
.b`8 +
7p\&D?
private void processErrorCode(int nErrorCode) g"Hl 30o
{ 3?<A]"X.
System.err.println("Error Code : " + nErrorCode); 1c@S[y
} h4itXJy52B
5(\/ b<#
7)1%Z{Dy
//停止文件下载 ]b>XN8y.
public void siteStop() g18zo~LZ
{ !gV{[j?~zr
bStop = true; :-U&_%#w
for(int i=0;i<nStartPos.length;i++) @:B}QxC
fileSplitterFetch.splitterStop(); Y@q9
oiR9NB&<
Z_dL@\#|
} THX% z `
} vol (%wB
//负责部分文件的抓取 },}g](!m
**FileSplitterFetch.java ]8OmYU%6V
*/ h+!R)q8M
package NetFox; etX(~"gG_
\p}GW
hP{+`\&<f
import java.io.*; k,'MmAz
import java.net.*; 0~_I9|FN
k:iy()n[
XYD-5pG
public class FileSplitterFetch extends Thread { J#j3?qrxu
<Piq?&VX[
ZybfqBTD&c
String sURL; //File URL Wl=yxJu_(
long nStartPos; //File Snippet Start Position TG8U=9qt
long nEndPos; //File Snippet End Position m5] a
int nThreadID; //Thread's ID 6&6dd_K(
boolean bDownOver = false; //Downing is over {|OXiRm'
boolean bStop = false; //Stop identical S76MY&Vx23
FileAccessI fileAccessI = null; //File Access interface YMNLn9
g,o46`6"
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8 l= EL7
{ ^*UtF9~%n
this.sURL = sURL; @`nG&U
this.nStartPos = nStart; %dr*dA'
this.nEndPos = nEnd; })kx#_o]'d
nThreadID = id; 1ljcbD)T;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C8qSoO4Z
} MQcIH2
p/u
ek/zQM@%
public void run() :5&UWL|
{ \+/ciPzA-
while(nStartPos < nEndPos && !bStop) DnhbMxh8o
{ 90Sras>F
k#~oagW_Gw
*81/q8Az
try{ sK9RViqF\
URL url = new URL(sURL); *wX[zO+o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [AIqKyIr
httpConnection.setRequestProperty("User-Agent","NetFox"); 9m_~Zs}Z
String sProperty = "bytes="+nStartPos+"-"; w8N1-D42
httpConnection.setRequestProperty("RANGE",sProperty); Y`$\o
Utility.log(sProperty); [euR<i*I#
qe?Ns+j<d
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InputStream input = httpConnection.getInputStream(); l O*
//logResponseHead(httpConnection); tQxxm=>
$_eJ@L#
&Qj1uf92.
byte[] b = new byte[1024]; Ma(Q~G .
int nRead; ~@QAa (P.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "|Yy"iB[
{ .X)Wb{7
nStartPos += fileAccessI.write(b,0,nRead); Ay^P#\VZ
//if(nThreadID == 1) -#G>`T~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,Csjb1
} [h&s<<# D
c=?6`m,"M
z?VjlA(X
Utility.log("Thread " + nThreadID + " is over!"); YwZx{%f
bDownOver = true; 2u5\tp?8
//nPos = fileAccessI.write (b,0,nRead); .V}bfd[k$
} XhWo~zh"
catch(Exception e){e.printStackTrace ();} o$U{.#
} 2ve<1+V_
} ypemp=+(r
-`z%<)!Y
n_Y7*3/b-o
//打印回应的头信息 0Krh35R_)F
public void logResponseHead(HttpURLConnection con) @;y@Hf'Jv
{ [ybK
for(int i=1;;i++) o /1+ }f
{ TXV^f*
String header=con.getHeaderFieldKey(i); aMkuyqPf{
if(header!=null) 8:*ZuR|~
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7)2Q
Utility.log(header+" : "+con.getHeaderField(header)); 9B83HV4J
else (JjxrZ+L
break; 9`VY)"rJ
} :9x]5;ma
} aTvLQ@MQ
}y J,&N'p
p0l.f`B
public void splitterStop() VQ2'a/s
{ M$>Nd6,@N
bStop = true; aZa1eE
} $[Nf?`f(t_
)"{}L.gC6
}vgM$o
} s[/d}S@ >
:M`~9MCRf
E[zq<&P@
/* saQo]6#
**FileAccess.java &t_TLV 8T
*//文件访问(定位，写) e}7!A
package NetFox; =;)=,+V~q
import java.io.*; :ec>[N~KG
3A~<|<}t
]-a/)8
public class FileAccessI implements Serializable{ [TqX"@4NS
u}_x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C8)s6
RandomAccessFile oSavedFile; ni )G
long nPos; tux`-F
"A~D(1K
8ql<7RTM!
public FileAccessI() throws IOException 4OO^%`=)M'
{ 1~2+w]-kU
this("",0); P%vouC0W
} ZnRj}y
KiE'O{Y
>Lo'H}[pF
public FileAccessI(String sName,long nPos) throws IOException M)wNu
{ Rp:I&f$Hk/
oSavedFile = new RandomAccessFile(sName,"rw"); )Wt&*WMFXl
this.nPos = nPos; @<4U &
oSavedFile.seek(nPos); E(1G!uu<
} CQ Ei(ty
10r!p:D
**AkpV)
public synchronized int write(byte[] b,int nStart,int nLen) yOXEP
{ 4&e<Sc64
int n = -1; maQxU(
try{ e8xNZG;
oSavedFile.write(b,nStart,nLen); jJ2{g> P0P
n = nLen; {3K]Q=
} 0lOan
catch(IOException e) 4W E)2vkS
{ $ER$|9)KD
e.printStackTrace (); _Vt9ckaA
} hM="9]i.
gOE?
KZ65#UVX
return n; /1.Z=@7
} TC=>De2;
[x`),3qD
f/0k,~,*
} M9~'dS'XI
zc,X5R1
n3eWqwQ$5
/* XI`s M~'
**SiteInfoBean.java W&I:z-VH
*/ GGZ9DC\{
package NetFox; ]1h9:PF
<9$Pl%:
\]S)PDqR
public class SiteInfoBean { I-kK^_0mV<
~Xr[d07bC
)lUocm
private String sSiteURL; //Site's URL o62GEl25
private String sFilePath; //Saved File's Path zpNt[F?~1
private String sFileName; //Saved File's Name <5h}\5#<j
private int nSplitter; //Count of Splited Downloading File I.SMn,N
+I:/8,&-x
1NrNTBI@
public SiteInfoBean() 91fZr
{//nSplitter的缺省值为5 lX50JJwk
//default value of nSplitter is 5 !SLfAFcS
this("","","",5); G \$x.
} R-4#y%k<
Gsm.a
6]HMhv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /7.//klN
{ K&-uW_0
sSiteURL= sURL; HA&hu/mw_
sFilePath = sPath; &=In
sFileName = sName; UZ:z|a3
this.nSplitter = nSpiltter; (8NE'd8
Q5 o0!w
7Fzr\&
} Cw5B p9
.^ba*qb`{
6"r _Y7%
public String getSSiteURL() lXVh`+X/l
{ 52'6wwv6?
return sSiteURL; C_h$$G{S(
} >LVGNicQ
JM*!(\Y
"5\6`\/
public void setSSiteURL(String value) YYe=E,q
{ I&% Z*H
sSiteURL = value; %9L+ Q1o
} ^=gN >xP
v++&%
sM9utR
public String getSFilePath() |NWHZo
{ v*OT[l7
return sFilePath; +z~bH!$2
} W*u$e8i7
PM)nw;nS
r#J_;P{U
public void setSFilePath(String value) ''p<C)Q
{ m:9|5W
sFilePath = value; ;):E 8;B)
} F&7^M0x\ O
!&{"tL@.
3/,}&SX
public String getSFileName() |Rm_8n%m
{ g6OPYUPg
return sFileName; xi)$t#K"
} 8RcLs1n/
Z~;rp`P
DjvPeX
public void setSFileName(String value) ]i>,oxBWe
{ \9R=fA18
sFileName = value; 0~Xt_rN](
} 0W)|n9
Q&w"!N
D8WKy
public int getNSplitter() xO4""/n
{ `yC[Fn"E^
return nSplitter; mp*?GeV?M
} nZEew.T:6
({cWb:+r
V \/Qik{h
public void setNSplitter(int nCount) 7ab'q&Y[
{ AN)r(86L
nSplitter = nCount; Fv:x>qZr@
} VKSn \HT~
} *Xh#W7,<
?[)V
dt/-0~U
/* t~":'le`zr
**Utility.java 7t/Y5Qf
*/ Yaz/L)Y;R
package NetFox; $v5 >6+-n
wZ=@0al
.fS{j$
public class Utility { 7JBr{3;eS
.0MY$0s
;Nd'GA+1;(
public Utility() v4Kf{9q#
{ tqjjn5!
QvJ29
-vc ,O77z"
} ScmwHid:\
bgkBgugZhX
//线程睡眠 86a,J3C[
public static void sleep(int nSecond) }'Ph^ %ox
{ K>n@8<7
try{ =)a%,H
Thread.sleep(nSecond); }ktK*4<k
} i`?yi-R&
catch(Exception e) 3_]QtP3
{ Y=y 0`?K
e.printStackTrace (); T&}KUX~Q/
} +RnWeBXAT
} )19#g1rn5
qLl4t/p
//日志 x6^FpNgQ
public static void log(String sMsg) O'QnfpQ*9
{ XXeDOrb
System.err.println(sMsg); MM( ,D& Z
} RJ{J~-q{
d@zxgn7o
rje;Bf
public static void log(int sMsg) $4og{
{ 9E|QPT
System.err.println(sMsg); KIKIag#
} I*/:rb
} -lXQQ#V -
q;_?e_
2EO9IxIf
/* @moaa}1
**TestMethod.java xn)F(P 0kv
*/ l>J%Q^
package NetFox; .k#O[^~]
"hZ `^"0b
/q/^B>]
public class TestMethod { 8cRc5X
, 10+Sh
n7zM;@{7
public TestMethod() 7nM<P4\
{ ///xx/weblogic60b2_win.exe m |.0$+=
try{ R@`xS<`L/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {}=5uU2Tu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =PnNett}a
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;6?,Yhk$h
fileFetch.start(); T~4HeEG>uH
} auM1k]
catch(Exception e){e.printStackTrace ();} r]kks_!Z
8 -w|~y';
+?5Vuc%
} ?*<1B
5r;)Ppo
CurU6x1
public static void main(String[] args) /Wdrpv-%,1
{ CI+liH
new TestMethod(); +LF=oM<
} $lJ!f
} OSom-?|w
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