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)); 32anmVnf
} Yh"9,Z&wiR
for(int i=0;i<nEndPos.length-1;i++) Lr\(7r
{ fMW=ss^fu-
nEndPos = nStartPos[i+1]; zT/woiyB`
} glM42s
nEndPos[nEndPos.length-1] = nFileLength; 67}8EV!/k
} 0v1~#KCm
} o@j!JI&
{LqYb:/C5U
>k=@YLj
//启动子线程 RCK*?\m5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P&Xy6@%[Z
for(int i=0;i<nStartPos.length;i++) 3qNuv];2
{ 8/,s8u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -{d(~XIo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [6.<#_~{
nStartPos,nEndPos,i); F60m]NUM)c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }I`o%GL
fileSplitterFetch.start(); |r+hj<K
} c1*^ \
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i{Q,>Rt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v6x jLP;O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NP~3!b
nEndPos = " + nFileLength); tI9p2!
// fileSplitterFetch[nPos.length-1].start(); ^y|`\oyqwN
!l.^]|
* "?,.
//等待子线程结束 LT,zk)5
//int count = 0; MfFmJ7>Bg
//是否结束while循环 kqC7^x
boolean breakWhile = false; we*E}U4
pm=s
=G'J@[d{d
while(!bStop) .0X 5Vy
{ biQ~q$E
write_nPos(); oVfRp.a
Utility.sleep(500); Q5Mn=
breakWhile = true; uBM%E OE
f=4q]y#& X
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for(int i=0;i<nStartPos.length;i++) y,<\d/YY@
{ ah!RQ2hDrV
if(!fileSplitterFetch.bDownOver) a'my0m
{ scd}{Y
breakWhile = false; "#%9dWy
break; j(_6.zf
} o1&Oug
} <2I<Z'B,e
if(breakWhile) 6WLq>Jo
break; *zX^Sg-[
P2U[PO
N&Uqzt*
//count++; dW|S\S'&
//if(count>4) Jy]}'eE?pr
// siteStop(); 9\6ZdnEKu,
} JU=4v!0
xw1n;IO4
Bjb8#n04
System.err.println("文件下载结束！"); p,OB;Ncf/
} XO/JnJ^B
catch(Exception e){e.printStackTrace ();} $\nAGmp@
} CX>QP&Gj
`ItPTSOi
<r8s=<:
//获得文件长度 x.U:v20`
public long getFileSize() M/8EaQs}
{ gBy7q09r
int nFileLength = -1; 59a7%w
try{ j"P}Wn
URL url = new URL(siteInfoBean.getSSiteURL()); I h 19&D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &8Oy*'
httpConnection.setRequestProperty("User-Agent","NetFox"); xJE26i
D{, b|4
*W1:AGpz
int responseCode=httpConnection.getResponseCode(); Lq5Eu$;r
if(responseCode>=400) 6vZ.CUK9
{ o~p%ODH
processErrorCode(responseCode); aK'%E3!~=x
return -2; //-2 represent access is error )9$>i5l
} l Gy`{E|
@ u2P&|:{
+"SYG
String sHeader; N51RBA
L]Dl}z
c UHKE\F
for(int i=1;;i++) |),3`*N
{ t3FfPV!P"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WB>M7MI%
//Utility.log(in.readLine()); #F|w_P
sHeader=httpConnection.getHeaderFieldKey(i); sT%^W
if(sHeader!=null) 4qLH3I[Y
{ + |d[q?
if(sHeader.equals("Content-Length")) ojy[<
{ HPeN0=7>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RS1c+]rr
break; a2`|6M;
} Zjkrne{
} #~>ykuq
else aYPD4yX"/
break; -c'~0g]<
} ,aQ{
} wT+b|K
catch(IOException e){e.printStackTrace ();} d(8X?k.S
catch(Exception e){e.printStackTrace ();} ojQjx|Q}
Ct,|g =(
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Utility.log(nFileLength); kc&MO`2 W\
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@{y[2M} %]
return nFileLength; {Kkut?5
} 982n G-"
jV!9IK;HA.
q_|YLs`
//保存下载信息（文件指针位置） {E+o+2L
private void write_nPos() BK16~Wl
{ W.t`
try{ XrD@q
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8KrqJN0\
output.writeInt(nStartPos.length); ?* %JGz_
for(int i=0;i<nStartPos.length;i++) yG<`7v
{ %uWq)D4r
// output.writeLong(nPos); +8\1.vY
output.writeLong(fileSplitterFetch.nStartPos); x^ruPiH
output.writeLong(fileSplitterFetch.nEndPos); +)eI8o0#
} 5bKm)|4z6
output.close(); 0pu=,
} P5^<c\Mr,Y
catch(IOException e){e.printStackTrace ();} W~e/3#R\=
catch(Exception e){e.printStackTrace ();} hLf<-NM
} O0VbKW0h3
`78:TU~5S
(s2ke
//读取保存的下载信息（文件指针位置） m$X0O_*A
private void read_nPos() "}(g3Iy
{ 93aRWEu3
try{ vdLBf+Zi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `x0GT\O2-
int nCount = input.readInt(); KPcOW#.T
nStartPos = new long[nCount]; E 9LKVs}
nEndPos = new long[nCount]; ]a}K%D)H
for(int i=0;i<nStartPos.length;i++) 9+o`/lk1
{ ~j&#DG&L
nStartPos = input.readLong(); YAvOV-L
nEndPos = input.readLong(); D|`I"N[<
} 0$~zeG"
input.close(); 2#y!(D8
} k15B5
catch(IOException e){e.printStackTrace ();} l6wN&JHTh
catch(Exception e){e.printStackTrace ();} cn~M:LW23
} pSvqGJU3
cy6lsJ"?
[Pnk@jIk4
private void processErrorCode(int nErrorCode) -t:~d:
{ ~x:B@Ow
System.err.println("Error Code : " + nErrorCode); TNHkHR[&
} EqV]/0-\
<oc"!c;T
,'E+f%
//停止文件下载 sKvz<7pag
public void siteStop() I}&`IUP
{ $Z!$E,@c
bStop = true; ,1}c% C*,Q
for(int i=0;i<nStartPos.length;i++) z ]@ Q
fileSplitterFetch.splitterStop(); aOj(=s
yJj$iri
=%O@%v
} ,'KQFC
} 2,nVo^13}
//负责部分文件的抓取 |N{?LKR %
**FileSplitterFetch.java TbY<(wrMZ
*/ R*v~jR/
package NetFox; YhVV~bvz*
_Py/,Ks.q
/ p_mFA]@
import java.io.*; P2q'P&
import java.net.*; 9 2e?v8
Y_H|Fl^
}3"FQ/6C
public class FileSplitterFetch extends Thread { errT7&@,A
Y'75DE<BC
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String sURL; //File URL rM sd)
long nStartPos; //File Snippet Start Position C1/<t)^
long nEndPos; //File Snippet End Position $[p<}o/6v]
int nThreadID; //Thread's ID yK$.wd2,
boolean bDownOver = false; //Downing is over :|GC~JElo5
boolean bStop = false; //Stop identical D2U")g}U
FileAccessI fileAccessI = null; //File Access interface tKnvNOhn
lcv&/ A
^^ Q'AE
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]/o0p
{ ]w3-No
this.sURL = sURL; O[N}@%HMW
this.nStartPos = nStart; %[x oA)0!
this.nEndPos = nEnd; S690Y]:h$v
nThreadID = id; | JmEI9n2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [@l:C\2
} *K{-J*
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public void run() Q: H`TSR]
{ Hcp)Q76X
while(nStartPos < nEndPos && !bStop) {Z529Ns
{ cGevFlnh
r[>=iim
DrG9Kky{
try{ h)W?8XdM
URL url = new URL(sURL); y+ZRh?2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;"*\R5a
httpConnection.setRequestProperty("User-Agent","NetFox"); n/ \{}9
String sProperty = "bytes="+nStartPos+"-"; ?,_$;g
httpConnection.setRequestProperty("RANGE",sProperty); }b//oe7
Utility.log(sProperty); ICJp-
$.a4Og2
H`js1b1n
InputStream input = httpConnection.getInputStream(); i\2d1Z
//logResponseHead(httpConnection); 4CzT<cp
X1A~#w>
]kJinXHW
byte[] b = new byte[1024]; j k%MP6
int nRead; *5SOXrvhu6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #].n0[
{ : ryE`EhB
nStartPos += fileAccessI.write(b,0,nRead); aV^wTs#2I
//if(nThreadID == 1) 7^{M:kYC!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *rY@(|
} eXHk6[%[
(*.t~6c?5
>L\>Th{o
Utility.log("Thread " + nThreadID + " is over!"); 3DNw=Ic0k
bDownOver = true; ]Iku(<*Ya
//nPos = fileAccessI.write (b,0,nRead); a3&&7n
} _\HMF
catch(Exception e){e.printStackTrace ();} yfBVy8Sm
} `MMh"# xN
} '6^20rj
6} DGEHc1
*O>OHX
//打印回应的头信息 c: /Wk
public void logResponseHead(HttpURLConnection con) =")}wl=s
{ VDCG 5QP6(
for(int i=1;;i++) EhEUkZE3)
{ CNC3">Dk~9
String header=con.getHeaderFieldKey(i); MYQZqlV
if(header!=null) fS08q9,S/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l8I`%bu
Utility.log(header+" : "+con.getHeaderField(header)); w\ hl2JTy
else X!} t``
break; UL81x72O
} sSisO?F!Z
} -WDU~VSU
QvM+]pdR6
L5%t.7B
public void splitterStop() jo75MSj
{ Nm{\?
bStop = true; oCE=!75
} ~F?vf@k
"O{_LOJ
VO_! +
} Z(fXN$
p2]@yE7w
8@Zg@>,
/* ^ olaq(z
**FileAccess.java hlY]s &0
*//文件访问(定位，写) ao4"=My*G
package NetFox; P`/;3u/P
import java.io.*; g@IV|C(*0
%4F Q~
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public class FileAccessI implements Serializable{ 2K^D%U
?xftr(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }ll&qb
RandomAccessFile oSavedFile; UDjmXQ2,
long nPos; gN2$;hb?
zf@gAvJ
XRZj+muTZ
public FileAccessI() throws IOException $;kFuJF
{ i!H)@4jX
this("",0); bve_*7CEM
} 20 <$f
"r!>p\.0O
4@2<dw|*h
public FileAccessI(String sName,long nPos) throws IOException p~Tp=d)/
{ HaJs)j
oSavedFile = new RandomAccessFile(sName,"rw"); MQs!+Z"m>
this.nPos = nPos; ,2t|(V*"&
oSavedFile.seek(nPos); gYeKeW3)
} oXC|q-(C
}ufzlHD
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public synchronized int write(byte[] b,int nStart,int nLen) `SFA`B)[5@
{ 9v\x&h
int n = -1; ~lBb%M
try{ '}4z=f`}
oSavedFile.write(b,nStart,nLen); a ~s:f5S>
n = nLen; `,lm:x+(0
} CbvP1*1
catch(IOException e) ;rggO0Y
{ \9HpbCHr
e.printStackTrace (); ~]sj.>P
} pUcN-WA
WqX$;'}h
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return n; y4\(ynk
} u+5&^"72,
kM:Z(Z7$
\ltbiDP2
} Z\YCjs%
{GH0> 1&
C VXz>oM
/* _4#Mdnh}[
**SiteInfoBean.java )WBp.j /#
*/ DpRGPs
package NetFox; c -sc*.&
&i(\g7%U
1>c^-"#e^
public class SiteInfoBean { !W\za0p
\m xi8Z w
1"\^@qRv#
private String sSiteURL; //Site's URL >='y+68
private String sFilePath; //Saved File's Path Ad}Nc"O
private String sFileName; //Saved File's Name z|M+ FHl$
private int nSplitter; //Count of Splited Downloading File JT,[;
+#RgHo?f
(DIMt-wz
public SiteInfoBean() +vr|J:
{//nSplitter的缺省值为5 +=Y[RCXT
//default value of nSplitter is 5 o?{-K-'B$
this("","","",5); "Wb>y*S
} 7&hhKEA
`o4%UkBpM
n8+_Uww
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W" i3:r
{ B*@0l:
sSiteURL= sURL; .)g7s? K
sFilePath = sPath; Fv} Uq\v[
sFileName = sName; 20,}T)}Tm
this.nSplitter = nSpiltter; Q)/oU\
oypF0?!m
f-BPT2U+
} 3j6Am{9
oHPh2b0
oazY?E]}3
public String getSSiteURL() PL|ea~/
{ f q&(&(|
return sSiteURL; uj~(r=%
} ]<BT+6L
&5y|Q?
m4on<5s/
public void setSSiteURL(String value) /tG[pg{[
{ @@z5v bs'{
sSiteURL = value; Kgw,]E&7
} [gIvB<Uv
S*NeS#!v
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public String getSFilePath() 4*&2D-8<K
{ z7s}-w,
return sFilePath; cz41<SFL
} S[e> 8
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no,b_0@N
public void setSFilePath(String value) }vEMG-sxX
{ sZ>0*S
sFilePath = value; {%D4%X<
} ?$6(@>`f&t
n >@Qx$-
QKIg5I-
public String getSFileName() ?/fC"MJq?
{ HP,{/ $i:
return sFileName; GGU>={D)
} 8^puC
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$#-O^0D
public void setSFileName(String value) 629ogJo8
{ *&~(>gNF,
sFileName = value; &&7&/
} hO2W!68
39bw,lRPV
v+~O\v5Q
public int getNSplitter() !>:]k?$b
{ ! Q8y]9O
return nSplitter; 0*,]`A=
} ZKJhmk
hm0MO,i"
|`'WEe2
public void setNSplitter(int nCount) 9vBW CCf
{ s;#,c(
nSplitter = nCount; xk7VuS*
} Ry40:;MYN
} 5nXmaj
sn8l3h)
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/* y$9XHubu
**Utility.java ]4B&8n!
*/ P1&Irwb`
package NetFox; pp+z5
9?uU%9r5P
N j:W6? A
public class Utility { )3ZkKv;zY
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A]MX^eY
public Utility() ;P^}2i[q>[
{ n2Y a'YF
L-Mf{z
-PaR&0Tt
} !O4)YM
|=[._VH1
//线程睡眠 i^)JxEPr w
public static void sleep(int nSecond) t')%;N
{ 2BO"mc<#$
try{ cRWYS[O?-
Thread.sleep(nSecond); A3|X`X
} t\O#5mo
catch(Exception e) bp'\nso/
{ <m*j1|^{t
e.printStackTrace (); vBV_aB1{
} /d>Jkv
} 6%MM)Vj+u
\^dYmU
//日志 $\L=RU!c}
public static void log(String sMsg) A27!I+M
{ ,7;euV5X
System.err.println(sMsg); A~;+P
} 26MoYO!k
M&KJZ
yY!@FGsA
public static void log(int sMsg) :M.]-+(
{ C#.27ah
System.err.println(sMsg); WL;2&S/{@
} vb$i00?
} 4+Y9":<
j3fq}>=
,#hNHFa'JH
/* @DlN;r?Cv
**TestMethod.java jWK>=|)=c
*/ 0QBK(_O`
package NetFox; ySHio;g9
)Mh5q&ow
:JK+V2B$H
public class TestMethod { >1q:-^
mzcxq:uZ5
<<&SyP
public TestMethod() v%S$5
{ ///xx/weblogic60b2_win.exe P%ZU+ET
try{ Efu/v<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V5+|H1=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v>5TTL~?
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5yf`3vV|3@
fileFetch.start(); jsq|K=x,
} 5oR)
catch(Exception e){e.printStackTrace ();} Hqb-)8 ~
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6G:7r [
} j^ttTq|l
v&xhS yZ
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public static void main(String[] args) uy([>8uu
{ jtPHk*>^wu
new TestMethod(); UM. Se(kS
} hmv*IF.
} QS<)*
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