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/G)E_
} BenUyv1d
for(int i=0;i<nEndPos.length-1;i++) "lnI@t{o
{ ]w/%>
nEndPos = nStartPos[i+1]; wQw&.)T
} T`W37fz0
nEndPos[nEndPos.length-1] = nFileLength; :8LK}TY7
} (Kg( 6E,
} AAc*\K
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//启动子线程 :zK\t5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LUKt!I0l
for(int i=0;i<nStartPos.length;i++) N /Fa^[
{ cMZ-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6}JW- sA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f7v|N)
nStartPos,nEndPos,i); []<N@a6VA>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @!KG;d:l
fileSplitterFetch.start(); UZ-[vD1n
} neBcS[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /I~(*X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $,8}3R5}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8;<3Tyjzu
nEndPos = " + nFileLength); "NvB@>S
// fileSplitterFetch[nPos.length-1].start(); G_v^IM#B=
HLb`'TC3r+
|_u|Td(n
//等待子线程结束 \H{UJ
//int count = 0; $Ma*qEB
//是否结束while循环 KYM%U"jD
boolean breakWhile = false; A|<i7QVY
/#Lm)-%G
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while(!bStop) ^X|Bzz)
{ bZCNW$C3l
write_nPos(); ZRn!z`.0
Utility.sleep(500); f5P@PG]{
breakWhile = true; 9iM[3uyO
7*(K%e"U
9D{p^hd
for(int i=0;i<nStartPos.length;i++) tk66Ggi[K
{ fD~f_Wr
if(!fileSplitterFetch.bDownOver) >o4Ih^VB
{ n_eN|m?@
breakWhile = false; ftRzgW);
break; s0/y> ok
} 2B[I- K s
} 'tJ@+(tqw
if(breakWhile) HSlAm&Y\
break; I;UCKoFT
L8~zQV$h
b@ OF
//count++; PwS7!dzH-
//if(count>4) ve*m\DU
// siteStop(); &d@N3y
} O)D+u@RhH
@,;VMO
H:4?sR3
System.err.println("文件下载结束！"); gV;9lpZ2
} .2x`Fj;o1
catch(Exception e){e.printStackTrace ();} v@Bk)Z
} >vZ^D
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~mk>9Gp
//获得文件长度 ,Wlw#1fP
public long getFileSize() 1+9}Xnxb
{ ,niQs+'<
int nFileLength = -1; =@s{H +
try{ DpvMY94Qh
URL url = new URL(siteInfoBean.getSSiteURL()); %3es+A@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fa2hQJ02
httpConnection.setRequestProperty("User-Agent","NetFox"); f<LRM
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g;\_MbfP
int responseCode=httpConnection.getResponseCode(); \!df)qdu
if(responseCode>=400) H&=fD` Xq
{ g&fq)d
processErrorCode(responseCode); 3)_(t.$D
return -2; //-2 represent access is error @ Br?
} R@lA5w
2T3b6
;bYLQ
String sHeader; a=AP*adx8
lJ(];/%
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for(int i=1;;i++) ;, ^AR{+x
{ IZ&FNOSZ+4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p{w:^l(
//Utility.log(in.readLine()); E#(dri*#t
sHeader=httpConnection.getHeaderFieldKey(i); "4WwiI9
if(sHeader!=null) ANlzF&K
{ #iAw/a0&
if(sHeader.equals("Content-Length")) 2}kJN8\F
{ #8i9@w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !H4C5wDu
break; !f)^z9QX8
} r@ v&~pL
} ;C~:C^Q\H
else UUDZ
break; 1aS66TS3
} KpfQ=~'
} "q3W&@
catch(IOException e){e.printStackTrace ();} @9\L|O'~?
catch(Exception e){e.printStackTrace ();} #s0Wx47~
k'PNfx\K
`c/mmS
Utility.log(nFileLength); ?.6fVSa
\KkAU6
\><v1x>;
return nFileLength; ;]Ko7M(4
} ;\rKkH"K8n
B;^YHWJ6i
d/l>~%bR
//保存下载信息（文件指针位置） D:fLQ8a
private void write_nPos() v<V9Z <ub
{ {7+y56[yu
try{ +~'ap'k m
output = new DataOutputStream(new FileOutputStream(tmpFile)); +uB.)wr
output.writeInt(nStartPos.length); VD+y4t'^
for(int i=0;i<nStartPos.length;i++) cnR18NK
{ :i/uRR
// output.writeLong(nPos); x|U[|i,;
output.writeLong(fileSplitterFetch.nStartPos); r"=6s/q7
output.writeLong(fileSplitterFetch.nEndPos); xL\R-H^c]
} OG{vap)
output.close(); t+2,;G
} TRku(w1f
catch(IOException e){e.printStackTrace ();} N\W4LO6
catch(Exception e){e.printStackTrace ();} DH'0#
} on)$y&lu
UCI !>G
\@F!h8e4
//读取保存的下载信息（文件指针位置） @{o3NR_
private void read_nPos() W'f)W4D$6
{ t[HA86X
try{ %C~LKs5oH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k/.a yLq
int nCount = input.readInt(); Rd>PE=u
nStartPos = new long[nCount]; V^qkHm e
nEndPos = new long[nCount]; a:}&v^v
for(int i=0;i<nStartPos.length;i++) OuV f<@a
{ d>}R3T
nStartPos = input.readLong(); Q}kXxud
nEndPos = input.readLong(); ;*q
} O`D,>=[
input.close(); 92=huV
} b";D*\=x
catch(IOException e){e.printStackTrace ();} !y-,r4\@`
catch(Exception e){e.printStackTrace ();} CINC1Ll_24
} o 12wp
aT20FEZ;
z P=3B%$
private void processErrorCode(int nErrorCode) hVdPO
{ yvt :/X
System.err.println("Error Code : " + nErrorCode); `;v>fTcy
} J6J|&Z~UT,
48"=,IrM
{B)-+0 6
//停止文件下载 UQ.DKUg
public void siteStop() Mt
{ y3Lq"?h
bStop = true; ];hK5
for(int i=0;i<nStartPos.length;i++) [zc8f
fileSplitterFetch.splitterStop(); 0mYKzJi
jR@J1IR<
0uwe,;
} Y0ouLUlI
} *|^}=ioj*
//负责部分文件的抓取 2/.I6IbL
**FileSplitterFetch.java drW}w+!
*/ Nc[[o>/Cb
package NetFox; IM*T+iRKqF
YCS8qEP&
j6r.HYX!
import java.io.*; I>(-&YbC
import java.net.*; >w)A~ F<
x'hUw*
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public class FileSplitterFetch extends Thread { Yb=Z`)
.jvRUD8A7
m5\/7 VC
String sURL; //File URL :+$/B N:iO
long nStartPos; //File Snippet Start Position EViQB.3w\
long nEndPos; //File Snippet End Position >cRE$d?
int nThreadID; //Thread's ID D<UX^hU
boolean bDownOver = false; //Downing is over >do3*koA
boolean bStop = false; //Stop identical ;@lC08SE
FileAccessI fileAccessI = null; //File Access interface Gz@/:dW^vZ
IPEJ7n49
O\ph!?L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Hsvu&>[`S
{ <6[P5>
this.sURL = sURL; z2DjYTm[~
this.nStartPos = nStart; _1U7@v:<@
this.nEndPos = nEnd; ebmU~6v k
nThreadID = id; R4q)FXW29
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rIo)'L$uU
} {*Tnl-m~
C|H/x\?zRv
\o=YsJ8U
public void run() 8CN~o|uN
{ i\94e{uty[
while(nStartPos < nEndPos && !bStop) &I=F4 z
{ LG>lj$hO
-naoM
<[w>Mbqj_
try{ n1 kh8,
URL url = new URL(sURL); YDoVm?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hB 36o9|9
httpConnection.setRequestProperty("User-Agent","NetFox"); OF/DI)j3
String sProperty = "bytes="+nStartPos+"-"; mjXO}q7
httpConnection.setRequestProperty("RANGE",sProperty); [lbe_G;
Utility.log(sProperty); g@][h_? {
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SJ;Kjq.Qo
InputStream input = httpConnection.getInputStream(); %X>P+6<=
//logResponseHead(httpConnection); 1@p'><\
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:rhh=nHgn
byte[] b = new byte[1024]; cO^}A(Ma(
int nRead; 2pn8PQfg)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vivU4:uH3
{ />[X k
nStartPos += fileAccessI.write(b,0,nRead); 7PG|e#
//if(nThreadID == 1) 3IHA+Zz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^s[OvJb
} .W1i3Z6g
-/z#?J\
"[M k5tM
Utility.log("Thread " + nThreadID + " is over!"); Z9vJF.clO
bDownOver = true; [S#QGB19
//nPos = fileAccessI.write (b,0,nRead); >UDb:N[
} Wi3St`$
catch(Exception e){e.printStackTrace ();} +(qs{07A$
} +PGtO9}B
} [yf&]0
|uRZT3bGyj
"Oj2B|:s&
//打印回应的头信息 6-vQQ-\
public void logResponseHead(HttpURLConnection con) - BE.a<
{ #V:28[
for(int i=1;;i++) QXg9ah~
{ s!Y`1h{
String header=con.getHeaderFieldKey(i); )/_T`cN
if(header!=null) XEvDtDR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0CFON2I
Utility.log(header+" : "+con.getHeaderField(header)); syR +;
else #:st>V_h
break; q;0QI{:5v
} ;*=MI/"N
} ~w9.}
#HF;yAc
#mK?K
public void splitterStop() hfQx$cv6
{ \yNe5
bStop = true; 4(O;lVT}
} s_`=ugue
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`SH#t3 5,
} ~D$?.,=l
,OilGTQ#
~!A*@aC
/* E`aAPk_y
**FileAccess.java e"]*^Q
*//文件访问(定位，写) F^bzE5#
package NetFox; ~+r"%KnG
import java.io.*; zJ7=r#b
k,UezuV
s1| +LT,D
public class FileAccessI implements Serializable{ U9ZWSDs
d9>k5!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?}D|]i34
RandomAccessFile oSavedFile; 1y)|m63&
long nPos; >nA6w$
@+(TM5Ub
Ebk_(Py\
public FileAccessI() throws IOException 5l ioL)
{ P.Uz[_&l6
this("",0); gk.c"$2
} Rz_fNlA
JDA:)[;
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public FileAccessI(String sName,long nPos) throws IOException WP b4L9<
{ K9 tuiD+j
oSavedFile = new RandomAccessFile(sName,"rw"); EX.`6,:+2
this.nPos = nPos; (ev(~Wc
oSavedFile.seek(nPos); alB[/.1
} vsU1Lzna6@
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public synchronized int write(byte[] b,int nStart,int nLen) )1!jv!
{ Q\ AM] U
int n = -1; ;#F7Fp*U
try{ ci~pM<+
oSavedFile.write(b,nStart,nLen); MsL*\)*s
n = nLen; $%ts#56*
} 0M^v%22
catch(IOException e) xct{Tv[FO
{ y:>'1"2`
e.printStackTrace (); @! gJOy
} D:yj#&I
/y.+N`_
rnV\O L
return n; }#3'72
} <E`Ygac
,( ?q
I2R" Y<
} G?t<4MTv
HpD<NVu
A_mVe\(*M
/* $aFCe}3b<
**SiteInfoBean.java >#Obhs|S{C
*/ bQ3EBJT{P
package NetFox; b?~%u+'3
O DLRzk(
bZB7t`C5
public class SiteInfoBean { 1oSrhUTy
$%3"@$
? !dy
private String sSiteURL; //Site's URL mEUdJvSG(
private String sFilePath; //Saved File's Path 2{sx"/k\A
private String sFileName; //Saved File's Name ^=lh|C\#
private int nSplitter; //Count of Splited Downloading File rv\yS:2
P!apAr
wePhH*nQ>
public SiteInfoBean() *h `P+_Q7
{//nSplitter的缺省值为5 (pl|RmmDz
//default value of nSplitter is 5 ^"?fZSC
this("","","",5); =y$|2(6
} *QIlh""6
5ZXP$.
D[NJ{E.{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1@}`dc
{ W8$ky[2R
sSiteURL= sURL; v%=@_`Ht
sFilePath = sPath; 0^L>J"o
sFileName = sName; :U}.
this.nSplitter = nSpiltter; TBGN',,
_=wu>h&7
B`)gXqBt
} VJeoO)<j
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"\x<Zg;
public String getSSiteURL() #'@pL0dj
{ 8{t^< j$n
return sSiteURL; zree}VqD;5
} 8)wxc1
9uNkd2#
gyt[ZN_2
public void setSSiteURL(String value) 0Q]ZS
{ kTjx.
sSiteURL = value; @&AUbxoj
} ?OYK'p.
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^{IF2_h"
public String getSFilePath() 3($cBC
{ +4N7 _Y
return sFilePath; N}j]S{j}'
} -8r';zR
/3VSO"kcZ
mO6rj=L^
public void setSFilePath(String value) CTG:C5OK
{ #s\HiO$BT
sFilePath = value; C3XB'CL6
} [%);N\o2Y
P0B`H7D
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public String getSFileName() $y0[AB|V
{ k"kGQk4
return sFileName; %|tDb
} e6 R<V]g
!>,\KxnM
/f5*KRM
public void setSFileName(String value) 4Pbuv6`RK
{ LkUYh3
sFileName = value; "}ms|
} rF3QmR?l
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m ll-cp
public int getNSplitter() b.LMJ'1
{ &zxqVI$4
return nSplitter; / bxu{|.
} IpJMq^Z
klwC.=?(j"
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public void setNSplitter(int nCount) 4P406,T]r
{ 6ka, FjJ\
nSplitter = nCount; VIXY?Ua
} a'[Ah2}3r<
} vDeb?n
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qy9RYIfZ
/* rwJCVkF
**Utility.java ,EE,W0/zzM
*/ YR 5C`o
package NetFox; P1r)n{;
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u%o]r9xl'
public class Utility { d;4LHQ0yU
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public Utility() Rz #&v
{ ~yGD("X
#cnh ~O
XTibx;yd<
} uPmK:9]3R
UgVLHwkvk
//线程睡眠 @PaOQ@
public static void sleep(int nSecond) I)JqaM
{ dHzQAqb8J
try{ pZ@)9c
Thread.sleep(nSecond); |g$n-t
} v_ U$jjO1
catch(Exception e) >-%}'iz+
{ @L9C_a
e.printStackTrace (); pL& Zcpx
} ,cesQ ou
} <-]qU}-
JNJ96wnX1
//日志 N<$dbqoT|
public static void log(String sMsg) V,*<E&+
{ RZ6[+Ygn
System.err.println(sMsg); b-`=^ny)K
} /O^aFIxk
'[Ue0r<jn
[f1'Qb
public static void log(int sMsg) Fv<^\q
{ Fx3CY W
System.err.println(sMsg); F3%8E<QZd;
} _K4E6c_
} 7xhBdi[ dQ
yMd<<:Ap
o#^(mGj_.
/* Bh#?:h&f
**TestMethod.java *\n-yx]
*/ h:4Uv}Z
package NetFox; Bp7`W:?#"
YV{^2)^
WLy%|{/
public class TestMethod { R [[ #r5q
vGX}zzto
$$5E+UDOs
public TestMethod() Ik\n/EE
{ ///xx/weblogic60b2_win.exe Z]QpH<Z
try{ '&;s32']}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oy _DYop
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <27:O,I
SiteFileFetch fileFetch = new SiteFileFetch(bean); .:b&$~<
fileFetch.start(); Fhk 8
} >iKbn
catch(Exception e){e.printStackTrace ();} jO5,PTV
Nuebxd
UG!528;7
} , S }
[Zpx :r}
~0 PR>QJ
public static void main(String[] args) l!d |luqbA
{ &>xd6-
new TestMethod(); (v)/h>vS
} DD?zbN0X
} -r'/PbV0
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