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)); XttqOf
} WegtyO
for(int i=0;i<nEndPos.length-1;i++) z MLK7+
{ Fd#?\r.
nEndPos = nStartPos[i+1]; "ZHW2l Mf
} s~X+*@.
nEndPos[nEndPos.length-1] = nFileLength; Ok>gh2e[c
} )iq-yjO6
} r`%+M7
og4UhP^UET
33jovK2
//启动子线程 NxSu3e~PS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BLN^ <X/
for(int i=0;i<nStartPos.length;i++) f5F@^QXQ
{ {zQS$VhXr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -r#X~2tPzD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Pa(^}n|
nStartPos,nEndPos,i); M@h|bN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OQ8 bI=?[x
fileSplitterFetch.start(); FSUttg"
} YRv&1!VLE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t(GR)&>.2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "8'@3$>R=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W-Fu-Cz=
nEndPos = " + nFileLength); 6Z#\CixG
// fileSplitterFetch[nPos.length-1].start(); ";BlIovT=R
XEC(P
=81@o,1w
//等待子线程结束 )Y]{HQd
//int count = 0; >a"Z\\dF
//是否结束while循环 'sLiu8G
boolean breakWhile = false; |UP `B|
YWMGB#=
PN0VQ/..
while(!bStop) a,3j,(3
{ {D!6%`HKV+
write_nPos(); !h(|\" }
Utility.sleep(500); 0OT\"O~S[
breakWhile = true; ` L>
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:gerQz4R8
for(int i=0;i<nStartPos.length;i++) %ThyOl@O
{ 7a#4tqM#
if(!fileSplitterFetch.bDownOver) vy_D>tp
{ $"dR SysB
breakWhile = false; %@;6^=
break; |l&vkRrN
} 3<k`+,'
} i:rFQ8I
if(breakWhile) umF Z?a
break; 8~9030>Q
IP``O!WP
gzBy?r> r
//count++; NB\{'
//if(count>4) u$*56y
// siteStop(); XW -2~?$
} #O$
!>BZ6gn5
P~s$EJL*
System.err.println("文件下载结束！"); &FH2fMLQ
} zG' "9kJx
catch(Exception e){e.printStackTrace ();} NZP.0coY
} CM<]ZG7
'eo KZX+
D\@m6=L
//获得文件长度 7SlsnhpW
public long getFileSize() R)F;py8)I
{ J8M$k/"X
int nFileLength = -1; !(n4|Wd
try{ aFe`_cnG
URL url = new URL(siteInfoBean.getSSiteURL()); T[,/5J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A#nun
httpConnection.setRequestProperty("User-Agent","NetFox"); WVmq% ,7
yu6`66h)
~7$&WzD
int responseCode=httpConnection.getResponseCode(); |J+(:{}~
if(responseCode>=400) s[K^9wz
{ +2K:qvzZ
processErrorCode(responseCode); N[<H7_/3
return -2; //-2 represent access is error cTXri8K_
} :N<.?%Kf
DUL4noq{
'WI^nZM
String sHeader; v1|Bf8
K,6b3kk
JOb*-q|y
for(int i=1;;i++) U3izvM
{ o]ag"Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Iq#ZhAk
//Utility.log(in.readLine()); EyI}{6~F
sHeader=httpConnection.getHeaderFieldKey(i); :U d
if(sHeader!=null) #Hvq/7a2R
{ ik"sq}u_]E
if(sHeader.equals("Content-Length")) 5aBAr
{ yf?h#G%24
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e/*$^i+S
break; OdQT2PA_
} ari7iF~j
} SFb{o<0 =
else $B#6tk~u
break; l"{Sm6:;-
} FYb34LY
} qC_mu)6
catch(IOException e){e.printStackTrace ();} zOHypazOTq
catch(Exception e){e.printStackTrace ();} Nrah;i+H\o
[w0/\]o
GyW.2
Utility.log(nFileLength); SR^_cpZoi
&m {kHM
f`8OM}un&
return nFileLength; }C /]
} B-*E:O0y
>S1)YKgz
yoRU_%xA
//保存下载信息（文件指针位置） `k;KBW
private void write_nPos() ? b[n|^wS
{ 1[E#vdbT
try{ 7 uMd ZpD
output = new DataOutputStream(new FileOutputStream(tmpFile)); T"T;`y@(
output.writeInt(nStartPos.length); `p0ypi3hn
for(int i=0;i<nStartPos.length;i++) W%e_~$H0
{ yMc:n"-[
// output.writeLong(nPos); v)f7};"z
output.writeLong(fileSplitterFetch.nStartPos); %d m-?`
output.writeLong(fileSplitterFetch.nEndPos); :Pq.,s
} &[a Tw{2
output.close(); ]DvO:tM
} o5Y2vmz?9
catch(IOException e){e.printStackTrace ();} 0rokR&Y-d
catch(Exception e){e.printStackTrace ();} 8ga_pNe
} p<`+sf}A:
a$9A(Pte
+'#oz+
//读取保存的下载信息（文件指针位置） DjCx~@
private void read_nPos() Jqr)V2Y
{ q (+ZwaV@
try{ aF8k/$u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0_yP\m
int nCount = input.readInt(); ,WWj-X|+=
nStartPos = new long[nCount]; 6<Hu8$G|
nEndPos = new long[nCount]; *zVvQ=
for(int i=0;i<nStartPos.length;i++) Zg:gY"^
{ *Q}[ ]g
nStartPos = input.readLong(); >0Ev#cX4
nEndPos = input.readLong(); 99OD=pxQ
} T~gW3J
input.close(); Y7U&Q:5'
} zzZg$9PT[
catch(IOException e){e.printStackTrace ();} BRbV7&
catch(Exception e){e.printStackTrace ();} %do1i W
} VjbG(nB?_
~ eN8|SR
nhdTTap&9
private void processErrorCode(int nErrorCode) z,*:x4}F
{ uD>z@J-v
System.err.println("Error Code : " + nErrorCode); qJ8-9^E,L
} \ Aq;Q?
`_ (~ Ud
(E($3t8
//停止文件下载 lQ*eH10H
public void siteStop() )u@c3?$6
{ =qoRS0Qa
bStop = true; V!|e#}1/
for(int i=0;i<nStartPos.length;i++) noA-)
fileSplitterFetch.splitterStop(); Fa3gJ[ZAqf
0jB X5
j%& IL0
} &1)xoZ'\
} 0H=9@
//负责部分文件的抓取 IlLn4Iw
**FileSplitterFetch.java 2HOe__Ns
*/ zp=!8Av
package NetFox; ;Gm>O7"|@
d,'!.#e
,9ml>ji`=
import java.io.*; 9Z!lmfnJ
import java.net.*; f =_^>>.
:d'65KMi
pZ+j[!
public class FileSplitterFetch extends Thread { ?ow'^X-
JmWR{du
{-*\w-~G
String sURL; //File URL rveVCTbC
long nStartPos; //File Snippet Start Position R "E<8w
long nEndPos; //File Snippet End Position kl{6]39
int nThreadID; //Thread's ID t.3\/
boolean bDownOver = false; //Downing is over b!~TAT&8
boolean bStop = false; //Stop identical l]vohLz 3!
FileAccessI fileAccessI = null; //File Access interface ~%aJFs
H2\1gNL
&d 3HB=x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1=TSJ2{9
{ \JU ~k5j
this.sURL = sURL; GAJ~$AiwHH
this.nStartPos = nStart; Pe,;MP\2
this.nEndPos = nEnd; |[wyc!nY).
nThreadID = id; a"qR J-@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u&3EPu
} m'.T2e.u
RV]a%mVlM
7x+=7,BZd
public void run() j7sU0"7^
{ T#e4":A&x
while(nStartPos < nEndPos && !bStop) LD@7(?mlU
{ tMG@K
M7U:g}
^fZGX<fH
try{ iQj2UTds3
URL url = new URL(sURL); vcOsq#UW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rIp'vy S\p
httpConnection.setRequestProperty("User-Agent","NetFox"); ;zm ks]
String sProperty = "bytes="+nStartPos+"-"; )v-Cj_W5]"
httpConnection.setRequestProperty("RANGE",sProperty); .q0AoM
Utility.log(sProperty); (.oaMA"B
Bb_}YU2#
^(m0M$Wk*
InputStream input = httpConnection.getInputStream(); YZ{jP?x
//logResponseHead(httpConnection); z qO$
^OjvL6A/p
!Pe1o-O
byte[] b = new byte[1024]; ]g7HEB.Y
int nRead; |3"NwM>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WxDb3l~
{ B^Bbso'{1
nStartPos += fileAccessI.write(b,0,nRead); &V FjHW
//if(nThreadID == 1) [M<{P5q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ylT6h_z1[Y
} e7hO;=?b'
0JrK/Ma3
?bn;{c;E
Utility.log("Thread " + nThreadID + " is over!"); 8t--#sDy{0
bDownOver = true; <Q\H
//nPos = fileAccessI.write (b,0,nRead); A@\qoS[
} VEr 6uvB
catch(Exception e){e.printStackTrace ();} ]zy~@,\
} 7s$6XO!
} T:dX4=z
=05iW
6S2r
//打印回应的头信息 ''%;EW>
public void logResponseHead(HttpURLConnection con) IMw "eV
{ CF,8f$:2
for(int i=1;;i++) @yCW8]
{ zL6 \p)y
String header=con.getHeaderFieldKey(i); A4}JZi6@
if(header!=null) tru;;.lj8K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b-,]A2.
Utility.log(header+" : "+con.getHeaderField(header)); V>1D1
else 2Ti" s-
break; %GNUnr$
} $hyqYp"/;
} #?L(#a$k
.jLMl*6%:
g?w2J6Z.`J
public void splitterStop() T$#FAEz
{ wBg<Q{J
bStop = true; DN4fP-m-
} `4$4bXrP'
"sz.v<F0:s
gcQ. YP9
} `wP/Zp{Hy
mOwWg
HVtr,jg
/* RPz!UMQSD
**FileAccess.java o+]Y=r2
*//文件访问(定位，写) 2U=/<3;u
package NetFox; -d$8WSI8
import java.io.*; [K"U_b}w
J-@o@!o
^4y(pcD
public class FileAccessI implements Serializable{ 5KL9$J9k
|@T5$Xg]5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H1aV}KD
RandomAccessFile oSavedFile; v_?s1+w
long nPos; d~togTs1
g:G%Ei~sF
Oz4,Y+[#
public FileAccessI() throws IOException d,GtH)(s
{ bLU^1S8Z
this("",0); ;'2`M
} UFzM#
FgFJ0fo
-13P 2<i+
public FileAccessI(String sName,long nPos) throws IOException el2*\(XT
{ }}4sh5z
oSavedFile = new RandomAccessFile(sName,"rw"); aTL8l.c2
this.nPos = nPos; FUW(>0x?
oSavedFile.seek(nPos); y(aAp.S>
} 1Pw(.8P
d- Z+fz
I,CAFq
public synchronized int write(byte[] b,int nStart,int nLen) uQ)JC7b\
{ . Ce&9l
int n = -1; :_{{PY0PK
try{ 7dM6;`V^
oSavedFile.write(b,nStart,nLen); ';;p8bv+
n = nLen; hJC p0F9O
} Dr8WV\4@
catch(IOException e) t+W=2w&
{ tdw\Di#m
e.printStackTrace (); [5Y$L
} 0gwm gc/#
|1<]o;:
@dWS*@
return n; i&}zcGC
} !TV_dKa
azR;*j8Q'
E&s'uE=w+
} O$<%z[
#TW>'lF
OUIUgej
/* sw=JUfAhy
**SiteInfoBean.java k+7M|t.?4
*/ 'Tru?y\
package NetFox; =jV%O$Fx
#pDGaqeX
c`$`0}
public class SiteInfoBean { iX>!ju'V
v8U1uOR,%
/BjGAa(
private String sSiteURL; //Site's URL C\a:eSgaC
private String sFilePath; //Saved File's Path ^M"=A}h
private String sFileName; //Saved File's Name evg7d
private int nSplitter; //Count of Splited Downloading File MWn L#!
aCH:#|B
/_VRO9R\V
public SiteInfoBean() {!{7zM%u0C
{//nSplitter的缺省值为5 C#**)
//default value of nSplitter is 5 |qy"%W@
this("","","",5); OFQi&/
} z:i X]df
TOPPa?=vk
LL$,<q%(P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R26tQbwE
{ )QSt7g|OF
sSiteURL= sURL; 8SCW.;0
sFilePath = sPath; OJ_2z|f<
sFileName = sName; |IcxegE
this.nSplitter = nSpiltter; ,5A>:2 zs
&TkbnDuYd~
DKVt8/vq
} .e _D3Xp<
"<.
~4~Tcn
public String getSSiteURL() ^/d^$
{ }DUDA%U
return sSiteURL; 1=q?#PQ
} 6U>jU[/
!^w\$cw&
@X6#$ex
public void setSSiteURL(String value) ;\*Od?1
{ @aD~YtL"n
sSiteURL = value; -SY:qG3?
} N;ecT@Ug
}AsF\W+5
V\M!]Nnxr
public String getSFilePath() h%w\O Z7
{ +@],$=aE?
return sFilePath; UWWD8~:
} 4Ig{#}<
qVRO"/R
hL{B9?
public void setSFilePath(String value) ]qza*ba
{ 4^NHf|UJH
sFilePath = value; wCTR-pL^
} gAUQQ
s^t1PfP(,
CG>2,pP,
public String getSFileName() PKM$*_LcGI
{ +e]b,9.sR
return sFileName; 4%v+ark8
} WZ6{(`;#m
5WJkeG ba
qCkg\)Ks5I
public void setSFileName(String value) rU^ghF
{ KW6" +,Th
sFileName = value; &CmkNm_B
} >(6\ C
)B&<Bk+
?{z${ bD
public int getNSplitter() ~m|?! ]n
{ -Us% g
return nSplitter; 2[YD&
} /bu<,o
FuiW\=^
n03SXaU~V
public void setNSplitter(int nCount) x71!r
{ !>@V#I
nSplitter = nCount; udy;Odt
} FC(cXPX}
} RMt vEa
\fR:+rbQ&|
h_G7T1;L
/* :(p rx
**Utility.java V1>94/waa
*/ U`p<lxRgQ
package NetFox; 842+KLS
hJ*E"{xs
%R"/`N9R,
public class Utility { !skiD}zd1
Kcdd=2 [T
-*l[:5m
public Utility() E=*Q\3G~
{ +&zCmkVC7
wP1VQUL
<_q/ +x]8
} p2vUt
Xgc\O08
//线程睡眠 OjEA;;qq
public static void sleep(int nSecond) LHz<=]?@
{ HbSx}bM_9
try{ WA\f`SRF
Thread.sleep(nSecond); Ru aJ9O
} $K fk=@
catch(Exception e) BvR3Oi@Wc
{ |3@Pt>Ikl
e.printStackTrace (); oP75|p
} >t}D5ah
} "FIx^
&.4_4"l(
//日志 m8^2k2
public static void log(String sMsg) -XG$ 0
{ d$~b`
System.err.println(sMsg); [te7uZv-
} EoCwS
:{Z^ _;Tf
k $&A
public static void log(int sMsg) W3rvKqdw5
{ K3D $ hb
System.err.println(sMsg); }PL
} O^%ace1
} ]m>MB )9
+[[gU;U"v
BniVZCct
/* 1&"1pH
**TestMethod.java Sd6^%YB
*/ tb\pjLB][
package NetFox; FCJ(D!
L-$g& -
F[Sat;Sll
public class TestMethod { iH0c1}<k$
ttVSgKAsm
%BLKB%5
public TestMethod() ^ s4|
{ ///xx/weblogic60b2_win.exe V%=t2+
try{ ;f~'7RKy!G
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >E=a~ O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1<|I[EI
SiteFileFetch fileFetch = new SiteFileFetch(bean); HI 61rXNF
fileFetch.start(); nHjwT5Q+Q
} ev >9P
catch(Exception e){e.printStackTrace ();} Y%@'a~
Bx>@HU
pBkPn+@
} /WVMT]T6^,
)&-E@% \
IPR396J+-
public static void main(String[] args) heA\6W:u&
{ ?K 0V#aq
new TestMethod(); 69yyVu_
} Xii#Qtd.
} 0in6z
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