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)); G~]BC#nB_
} 3/e !7
for(int i=0;i<nEndPos.length-1;i++) 1%+^SR72
{ D5p22WY
nEndPos = nStartPos[i+1]; FN R& :
} k);!H+
nEndPos[nEndPos.length-1] = nFileLength; 3YRzBf:h
} r__M1 !3
} %Fv)$ :b
#?*jdN:
h CiblM
//启动子线程 6xe |L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ep!.kA=\
for(int i=0;i<nStartPos.length;i++) (`p(c;"*C!
{ /$=^0v+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zyr6Tv61U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZZ(@:F
nStartPos,nEndPos,i); 24Fxx9g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *8p</Q
fileSplitterFetch.start(); GM/1ufZH
} |3LMVN
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q'VS]n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rUO{-R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7,zARWB!?
nEndPos = " + nFileLength); On^#x]
// fileSplitterFetch[nPos.length-1].start(); 8{YxUD
V("1\
_biJch
//等待子线程结束 D/WS
//int count = 0; LcXMOT)s
//是否结束while循环 OOCeZ3yF(
boolean breakWhile = false; \abl|;fj
S(6ZX>wv:
"ir*;|
while(!bStop) EHZSM5hu
{ "Tv7*3>
write_nPos(); ~-+Zu<
Utility.sleep(500); LDsYr]
breakWhile = true; FScQS.qF
?>Aff`dHY
KB= z{g
for(int i=0;i<nStartPos.length;i++) f<wgZM
{ Tt\w^Gv\d
if(!fileSplitterFetch.bDownOver) [P/gM3*'
{ v(iUo&Ge
breakWhile = false; sfa'\6=O
break; b5Pn|5AVj
} Q6K)EwN
} Ie"R,,c
if(breakWhile) (4LLTf0
break; 6{'6_4;Fv(
2XHk}M|
F0Hbklr
//count++; &[kgrRF@HU
//if(count>4) Kxn7sL$]=F
// siteStop(); o3=kF
} u$#7W>R
{rZ"cUm
WIm7p1U#V
System.err.println("文件下载结束！"); <Xx\F56zp
} I8?[@kg5b'
catch(Exception e){e.printStackTrace ();} Kcl$|T
} #A;Z4jK
AX+d?M
''uI+>Y
//获得文件长度 ~\ f^L?m
public long getFileSize() UsN b&aue
{ lG9ARRy(=
int nFileLength = -1; b U NYTF{
try{ 7VcVI? ?
URL url = new URL(siteInfoBean.getSSiteURL()); n^N]iw{G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >U?Bka!
httpConnection.setRequestProperty("User-Agent","NetFox"); lWvd"Vlt
^A`(
M;qL)vf
int responseCode=httpConnection.getResponseCode(); l #Q`f.
if(responseCode>=400) 7h1gU
{ jm\#($gl=
processErrorCode(responseCode); #Uh5tc
return -2; //-2 represent access is error I?>T"nV +'
} )\vHIXnfJ1
*a!!(cZZ
dn_OfK
String sHeader; 4-_lf(#i
P-[K*/bPw
sv"mba.J
for(int i=1;;i++) I})t
{ #~;8#!X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2<Bv=B
//Utility.log(in.readLine()); @88i/ Z_
sHeader=httpConnection.getHeaderFieldKey(i); Ky#B'Bh}`g
if(sHeader!=null) ^z^e*<{WEl
{ I!gj;a?R
if(sHeader.equals("Content-Length")) X vMG09
{ PU5mz.&0'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]0 RXo3
break; Hs=N0Sk]j
} 493i*j5r)l
} 4iqmi<[("
else DWQQ615i
break; e oSM@Isu
} |SKG4_wGe
} SzX~;pFM0
catch(IOException e){e.printStackTrace ();} R Sz[6
catch(Exception e){e.printStackTrace ();} t<F]%8S
bpa O`[*
]31XX=
Utility.log(nFileLength); D|j\ nQ
u3mT l
]fo^43rn{
return nFileLength; 8G&+
} E5G"QnxR>N
vUe *
,$zlw\
//保存下载信息（文件指针位置） I0+wczW,^
private void write_nPos() '<< ~wt
{ Uy5!H1u
try{ %@n8 ?l4
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1Dp@n
output.writeInt(nStartPos.length); _G #"B{7
for(int i=0;i<nStartPos.length;i++) 'h>5&=r
{ lc7a@qnw
// output.writeLong(nPos); bDBO+qA
output.writeLong(fileSplitterFetch.nStartPos); /1~|jmi(
output.writeLong(fileSplitterFetch.nEndPos); 'QojSq
} (0#F]""\e
output.close(); 5;8B!%b
} \K~fRUo]=c
catch(IOException e){e.printStackTrace ();} 1]Q2qs
catch(Exception e){e.printStackTrace ();} #0hNk%X=
} ]/Yy-T#@
dyiEK)$h
?%/u/*9rj
//读取保存的下载信息（文件指针位置） 68<Z\WP
private void read_nPos() ~X<cG=p~u
{ 7[v@*/W@
try{ V!77YFen %
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y%:0|utQC
int nCount = input.readInt(); in#]3QGV
nStartPos = new long[nCount]; m+2`"1IE[
nEndPos = new long[nCount]; yISQYvSN
for(int i=0;i<nStartPos.length;i++) aT:AxYn8
{ L'XdX\5
nStartPos = input.readLong(); |F@xwfgb
nEndPos = input.readLong(); 3'*%R48P`
} hr4ye`c j
input.close(); Nv?-*&L
} |"YA<e %
catch(IOException e){e.printStackTrace ();} /CI%XocB
catch(Exception e){e.printStackTrace ();} 1Uemsx%'k
} q7f;ZK=f
?Wg{oB@(
*UBP]w
private void processErrorCode(int nErrorCode) }"?nU4q;S
{ Zxc7nLKF~
System.err.println("Error Code : " + nErrorCode); $@_t5?n``F
} <2O7R}j7v
gZlw
\DU^idp#
//停止文件下载 (;pi"/x[
public void siteStop() M?xpwqu\
{ zf3:<CRX5
bStop = true; Va@6=U7c
for(int i=0;i<nStartPos.length;i++) T3 9C lH
fileSplitterFetch.splitterStop(); X')Zm+
VP%i1|XZJ
%7v@n+Q
} kg: uGP9
} ^+%tlX_+.
//负责部分文件的抓取 9#&W!f*qO|
**FileSplitterFetch.java l^ 0_>R
*/ >*= =wlOB
package NetFox; q)V1{B@
twtkH~`"Q
O5qW*r'
import java.io.*; u-QO>3oY6
import java.net.*; 2zKo
z_Wm HB
Yn4)Zhkk
public class FileSplitterFetch extends Thread { [.j]V-61
#PslrA. E
w3=)S\
String sURL; //File URL FL`1yD^2
long nStartPos; //File Snippet Start Position O~h94 B`
long nEndPos; //File Snippet End Position (D>y6r>r
int nThreadID; //Thread's ID Ni!;-,H+E
boolean bDownOver = false; //Downing is over k%]DT.cE
boolean bStop = false; //Stop identical M U?{?5
FileAccessI fileAccessI = null; //File Access interface xaWGa1V'z
h41$|lonU%
NFY|^*bll
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cZe'!CQS
{ tS (i711
this.sURL = sURL; ESD<8OR
this.nStartPos = nStart; -VWCD,c
this.nEndPos = nEnd; j,=*WG
nThreadID = id; ?""\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M'umoZmW0
} 4|6&59?pnc
BbrT f"`
Y9i9Uc.]
public void run() }PI35i1!t
{ ik2- OM
while(nStartPos < nEndPos && !bStop) +ze}0lrEL
{ =a)iVXSB]
{_zV5V
\E$1lc
try{ @7@e`b?
URL url = new URL(sURL); W$" Y%^L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h L]8e>a?
httpConnection.setRequestProperty("User-Agent","NetFox"); z;dcAdz9
String sProperty = "bytes="+nStartPos+"-"; k,,!P""
httpConnection.setRequestProperty("RANGE",sProperty); b JfD\
Utility.log(sProperty); bQwdgc),s{
{sC@N![
)L |tn
InputStream input = httpConnection.getInputStream(); bZ>&QM
//logResponseHead(httpConnection); *o02!EYge
H]_WFiW-9
vWU%ST
byte[] b = new byte[1024]; '7xxCj/*
int nRead; $D QD$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xLx"*jyL
{ K2cq97k,d
nStartPos += fileAccessI.write(b,0,nRead); >|a\>UgC
//if(nThreadID == 1) 7E$eN8H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3sZ,|,ueD
} /Hv*K&}M
,b<9?PM
i8Fs0U4"
Utility.log("Thread " + nThreadID + " is over!"); T3PX gL)o
bDownOver = true; ^|wT_k\
//nPos = fileAccessI.write (b,0,nRead); WP0 #i~3*
} /M3y)K`^
catch(Exception e){e.printStackTrace ();} i2$*}Cu
} },DyU
} bh6d./
[ULwzjss#L
4~O6$;!|~
//打印回应的头信息 Zc-#;/b3T
public void logResponseHead(HttpURLConnection con) "r8EC
{ +XEjXH5K
for(int i=1;;i++) K`hz t
{ u_N\iCYp
String header=con.getHeaderFieldKey(i); :T_'n,
if(header!=null) |d $1wr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .Y!;xB/
Utility.log(header+" : "+con.getHeaderField(header)); $ZQ"({<w<g
else F9MR5O"
break; LeY+p]n~
} q*L ]
} 4,2(nYF
1g1?zk8zO
4P|$LkI
public void splitterStop() 6|,e%
{ i90}Xyt
bStop = true; @l'G[jN5
} (lb6]MtTHY
R6`*4zS
Sv7 i! j
} Mx8Gu^FW.d
@]f3|>I
u7HvdLql
/* >;)2NrJV
**FileAccess.java h$70H^r
*//文件访问(定位，写) 0Cl,8P
package NetFox; <B!'3C(P
import java.io.*; CoU3S,;*
=HVfJ"vK
Pg/T^n&
public class FileAccessI implements Serializable{ N31?9GE
bFg*l$`5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qxfLfgu^
RandomAccessFile oSavedFile; 8O6_iGTBh
long nPos; 4otl_l(`yv
A t{U~^
:q^R `8;(t
public FileAccessI() throws IOException wa!zv^;N*
{ !\^jt%e&
this("",0); XYjcJ
} +0J@y1
ABc)2"i:*
YZ+>\ x
public FileAccessI(String sName,long nPos) throws IOException 6B#('gxO
{ QC{u|
oSavedFile = new RandomAccessFile(sName,"rw"); |8H_-n
this.nPos = nPos; U;g S[8,p
oSavedFile.seek(nPos); Sk\n;mL:
} ahA{B1M)n
7rcA[)<'
^ Hg/P8q
public synchronized int write(byte[] b,int nStart,int nLen) eIg+PuQD]
{ f])M04<
int n = -1; 3?2<WEYr
try{ ?q_^Rj$
oSavedFile.write(b,nStart,nLen); zG#wu
n = nLen; Q&xjF@I
} mQ}Gh_'ps
catch(IOException e) ;WD,x:>blO
{ f^p^Y F+
e.printStackTrace (); EUy(T1Cl&&
} xYI;V7
.n`( X#,*l
:?=Q39O9
return n; XA)'=L!^
} mG2VZ>
N5?IpE
~-_i
} gWOt]D&#/
#{$1z;i?f
sw$2d
/* H\E7o"m
**SiteInfoBean.java %X>FVlPm
*/ URA0ey`
package NetFox; ]tB@kBi "
f#$|t>
R_1qn
public class SiteInfoBean { ~U$":~H[
+@ MPQv
s\gp5MT
private String sSiteURL; //Site's URL nO{ x^b <
private String sFilePath; //Saved File's Path nA_%2F'W}
private String sFileName; //Saved File's Name {,?ss$L
private int nSplitter; //Count of Splited Downloading File iA'As%S1
/[K_ &
m`y9Cuk
public SiteInfoBean() S`m,S4-eD
{//nSplitter的缺省值为5 j13DJ.xu
//default value of nSplitter is 5 R>2IRvY(
this("","","",5); I{ ryD -!
} 6Ps.E
?59'dGnz_
Zw{MgoJ0Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M0L&~p_F
{ %2"J:0j
sSiteURL= sURL; E!J=8C.:
sFilePath = sPath; 8#X_#
sFileName = sName; PLA#!$c7q
this.nSplitter = nSpiltter; _c2WqQ-05
m\ S\3n
7Xg?U'X
} WC*=rWRxF
rrqQCn9
gEwd &J
public String getSSiteURL() Gb2L }
{ 4^*,jS-9g}
return sSiteURL; q.Jsf+
} ])w[
|=6_ xRyr
9b"MQ[B4#a
public void setSSiteURL(String value) UDEj[12S
{ tfYB_N
sSiteURL = value; |3shc,7
} 6>`c1 \8f
TL0[@rr4
WsI>n
public String getSFilePath() };,/0Fu
{ v.&>Ih/L
return sFilePath; jlqv2V7=/
} /,s[#J
}Fa%%}
W)*p2#l
public void setSFilePath(String value) 5~H#(d<oZ
{ ZmEEj-*7s
sFilePath = value; DyO$P#~?
} ZU{4lhe
=0qpVFvU
Y?K{(szo ?
public String getSFileName() d2N:^vvvR
{ 0w=R_C)s
return sFileName; W!T"m)S
} Jr;jRe`4c
,7_4z]jK
h-#1U3d
public void setSFileName(String value) LP];x3
{ #8XL :I
sFileName = value; k@dN$O%p
} 7f{=w, U
\ZI'|Ad
;# uZhd
public int getNSplitter() ?D`T7KSe~D
{ ?6^|ZtB
return nSplitter; T,%j\0
} K`g7$r)U[
n.}E5%qK
Cbm\h/PXl
public void setNSplitter(int nCount) `aC){&AP(
{ . pzC5Ah
nSplitter = nCount; z (?=Iv3
} m ci/'b Xt
} Wb}c=hZv
yQNV@T<o
P"/G
/* n>>Qn&ym
**Utility.java k,yZ[n|`
*/ 5=|hC3h
package NetFox; j|4C\~i
v\tEVhm
'cix`l|^
public class Utility { kF"@Ngv.
@#g<IBG=*
ar9]"s+'
public Utility() ;r[@v347
{ HlvuW(,x=
W2FD+ wt
_tTNG2
} gKYfQ+
$5D,sEC@
//线程睡眠 E_e6^Sk5B(
public static void sleep(int nSecond) .mLK`c6
{ f y:,_#
try{ myl+J;,]
Thread.sleep(nSecond); +ZM)bbB
} ="wzq+U
catch(Exception e) y*pUlts<
{ l*\y
e.printStackTrace (); PYbVy<xc
} i0$Bx>
} *t[. =_v
E:9"cxx
//日志 #S&Tkip]"W
public static void log(String sMsg) /DQaGq/Ld
{ 2'EUy@0
System.err.println(sMsg); CHrFM@CM
} ,(8;y=wux
( +pLA"xq
aT>'.*\]
public static void log(int sMsg) mGp.3{j
{ if|+EN%
System.err.println(sMsg); <Ln1pV~k
} S}p4iE"n
} |7yAX+
P9g en6
V=:'SL*3|
/* \7Jg7*
**TestMethod.java V-<GT?
*/ g35DV6
package NetFox; Tq]Sn]CSP
=jB08A
[<DZ*|+
public class TestMethod { At7>V-f}
&l3iV88
Oo"^%F~%
public TestMethod() Ag{iq(X
{ ///xx/weblogic60b2_win.exe d&ex5CU5
try{ ^*P%=>zO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &boOtl^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zt.'K(]2h
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y. ,Kl~
fileFetch.start(); j@YU|-\qh
} ZI=%JU(
catch(Exception e){e.printStackTrace ();} "@??Fw!
$s9Vrw0Z
0TQ$C-%
} uc;8 K,[t
n4}Br;%
?b(=1S\E'^
public static void main(String[] args) !%"8|)CAr
{ "jG}B.l=,
new TestMethod(); G6T_O
} xuqv6b.
} a)wJT`xu
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