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)); < d]|5
} kal8k-$#
for(int i=0;i<nEndPos.length-1;i++) !Q#b4f
{ l:ED_env:
nEndPos = nStartPos[i+1]; CxRp$;rk
} WLpn,8qsY
nEndPos[nEndPos.length-1] = nFileLength; wiVQMgi`
} ?1{`~)"
} d.+vjMI
Y[H_?f=;%
j\vK`.z
//启动子线程 kgIWgk%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <,GHy/u\
for(int i=0;i<nStartPos.length;i++) 1t0FJ@)*
{ EK'&S=]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `~RV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D6vn3*,&
nStartPos,nEndPos,i); 7^; OjO@8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d#*5U9\z
fileSplitterFetch.start(); Z^|C~lp;n
} ArEpH"}@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `8-aHPF-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !G,$:t1-=V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^Pf&C0xXv
nEndPos = " + nFileLength); Fv: %"P^
// fileSplitterFetch[nPos.length-1].start(); 4"2/"D0
c,qCZ-.Sg
)k1,oUx
//等待子线程结束 U&5zs r
//int count = 0; SQ!lgm1bA
//是否结束while循环 ]UI+6}r
boolean breakWhile = false; t[maUy_A
CvW((<?
+wSm6*j7=
while(!bStop) LJ))
{ e.+)0)A-
write_nPos(); '2tEKVb
Utility.sleep(500); cg.e(@(
breakWhile = true; vraU&ze\1
q+z\Y?
F:g{rm[
for(int i=0;i<nStartPos.length;i++) 3azc`[hl
{ )eEvyU
if(!fileSplitterFetch.bDownOver) ob7_dWAG
{ 'k67$H
breakWhile = false; s,v#lJ]d0W
break; EVL;"
} /$z@_U[L
} v(h Xk]S
if(breakWhile) OgS8.wX
break; of`]LU:
*\WI!%
`Y;gMrp
//count++; }^<zVdwp
//if(count>4) FNM"!z
// siteStop(); :U q]~e
} _e_%U<\4
t4*A+"~j
%MJ7u}
System.err.println("文件下载结束！"); 0q>lW &J
} ;5k|gW
catch(Exception e){e.printStackTrace ();} C6M/$_l&a
} `.W;ptZ6
[8P2V
xW9 s[X
//获得文件长度 Z ~9N
public long getFileSize() PoJyWC
{ weV#%6=5\
int nFileLength = -1; pCUOeQL(
try{ 2S6EDXc
URL url = new URL(siteInfoBean.getSSiteURL()); \,!q[nC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fti|3c
httpConnection.setRequestProperty("User-Agent","NetFox"); 1^#Q/J,
Bqi2n'^O2
*`-29eR"8
int responseCode=httpConnection.getResponseCode(); .^S78hr]n
if(responseCode>=400) {Yk20Zn
{ mv?H]i`N
processErrorCode(responseCode); ~k0)+D}
return -2; //-2 represent access is error *F*fH>?C#
} S1`0d9ds#
E`n`#=xKR
PJ@,01
String sHeader; *UoHzaIqz
"T%'Rp`j|
xg^^@o
for(int i=1;;i++) @%nUfG7TQ
{ X9A[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |a$w;s>\
//Utility.log(in.readLine()); ]~Vu-@ /}
sHeader=httpConnection.getHeaderFieldKey(i); #ljg2:I+
if(sHeader!=null) pf@}4PN}
{ *.c9$`s
if(sHeader.equals("Content-Length")) )xx/di
{ 50aWFJYw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ti|++oC/&
break; T\!SA
} T;r];Y(b*
} (OcNC/9
else )v{41sM+
break; -xu.=n@,
} by]|O
} <1+6O[>{
catch(IOException e){e.printStackTrace ();} ~:<@`
catch(Exception e){e.printStackTrace ();} !b->u_
7 eQoc2X2
j4xr1y3^
Utility.log(nFileLength); ^s~n[
6q[!X0u
,."(Gp
return nFileLength; h_chZB'
} E D^rWE_
62l0 Z-
|id79qY7g
//保存下载信息（文件指针位置） XQJ^)d00h
private void write_nPos() s!/holu
{ XH:gQ9FD
try{ fk7Cf"[w
output = new DataOutputStream(new FileOutputStream(tmpFile)); NZC='3Uz
output.writeInt(nStartPos.length); B/D\gjb
for(int i=0;i<nStartPos.length;i++) ,V]A63J
{ n~ >h4=h
// output.writeLong(nPos); +F~0\#d
output.writeLong(fileSplitterFetch.nStartPos); iQzX-a|4]
output.writeLong(fileSplitterFetch.nEndPos); T[XP\!z]B!
} :n4:@L<%H
output.close(); +>:}req
} 27],O@2?L
catch(IOException e){e.printStackTrace ();} /1W7<']>xV
catch(Exception e){e.printStackTrace ();} n*i'vtQ8
} ow+Dd[i
EdAR<VfleA
A]iv)C;]
//读取保存的下载信息（文件指针位置） k g,ys4
private void read_nPos() hHc^ZA
{ RQpIBsj
try{ 2WPF{y%/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i$JG^6,O
int nCount = input.readInt(); ]fADaw-R
nStartPos = new long[nCount]; .5!sOOs$P
nEndPos = new long[nCount]; %-ZR~*
for(int i=0;i<nStartPos.length;i++) mbX)'. +L
{ E/7vIg F
nStartPos = input.readLong(); s1Tl.p5
nEndPos = input.readLong(); ,|.*,
} ~njbLUB
input.close(); qHR^0&
} Cl9SPz
catch(IOException e){e.printStackTrace ();} F!)M<8jL&9
catch(Exception e){e.printStackTrace ();} 14rVb2^
} .:Bwa
zyZok*s
"37@Zt
private void processErrorCode(int nErrorCode) nGv23R(?G
{ 2z.8rNwT
System.err.println("Error Code : " + nErrorCode); " _:iK]
} +% XhQ
Sj0 ucnuHi
XewXTd#x
//停止文件下载 s("Cn/ZkS
public void siteStop() ;5D@kS^
{ i.&Kpw9;m
bStop = true; XSp x''l
for(int i=0;i<nStartPos.length;i++) jom}_
fileSplitterFetch.splitterStop(); GSGyF
I mPu}
UAx.Qq
} %oh`EGmVP
} UH 47e
//负责部分文件的抓取 /o|PA:6J
**FileSplitterFetch.java \ W 'i0+
*/ CGd[3}"
package NetFox; GJC!0{8;
*(d6Z#
s%N`
import java.io.*; Mhv1K|4s
import java.net.*; }fJ:wku
rnn2u+OG
{d1N&
public class FileSplitterFetch extends Thread { QiTR-M2C!
abROFI5.L
$u; >hk
String sURL; //File URL R3B5-^s
long nStartPos; //File Snippet Start Position `26V`%bPkr
long nEndPos; //File Snippet End Position 0'yG1qG
int nThreadID; //Thread's ID smfG,TI
boolean bDownOver = false; //Downing is over ?w]"~
boolean bStop = false; //Stop identical c~gNH%1XN
FileAccessI fileAccessI = null; //File Access interface 'v\1:zi
5JBB+g
>JKnGeF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]aC':55(
{ %[]"QbF?
this.sURL = sURL; L$Hx?^3
this.nStartPos = nStart; z(g%ue\
this.nEndPos = nEnd; a=J@yK
nThreadID = id; iK5]y+@8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +{,N X
} Vs_\ykO
r6d0x
MzEm*`<
public void run() HGO#e
{ I~\O
while(nStartPos < nEndPos && !bStop) /d0Q>v.g
{ T}n N=Q4
^>N8*=y
Q`.'-iq
try{ jo9J%vo
URL url = new URL(sURL); `z9)YH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2d-TU_JqX
httpConnection.setRequestProperty("User-Agent","NetFox"); VHXI@UT*
String sProperty = "bytes="+nStartPos+"-"; "gXxRHTX
httpConnection.setRequestProperty("RANGE",sProperty); /=8O&1=D
Utility.log(sProperty); >I$B=
dT5J-70Fl
&`9j)3^J.
InputStream input = httpConnection.getInputStream(); e>L5.~i
//logResponseHead(httpConnection); A",eS6
]b4pI*:$I
xS=_yO9-
byte[] b = new byte[1024]; <8u>_o6
int nRead; 0JmFQ^g(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R%>jJ[4\[
{ ,>D ja59
nStartPos += fileAccessI.write(b,0,nRead); 8[8|*8xqs
//if(nThreadID == 1) @%6)^]m}r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cC^W2\
} 9@:BK;Fi
v6wRME;JA
JB&G~7Q85
Utility.log("Thread " + nThreadID + " is over!"); y,MPGW_
bDownOver = true; Z5((1J9
//nPos = fileAccessI.write (b,0,nRead); jCU=+b=
} \Dn&"YG7
catch(Exception e){e.printStackTrace ();} z%OuI 8"'
} R=!kbBK>\
} &MCy.(jN
L +L9Y}
;tJWOm
//打印回应的头信息 T"n{WmVQ
public void logResponseHead(HttpURLConnection con) -glugVq
{ JZ`>|<W
for(int i=1;;i++) 8O,?|c=>
{ "hL9f=w
String header=con.getHeaderFieldKey(i); {DU"]c/S
if(header!=null) ^#]c0
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?nQ_w0j
Utility.log(header+" : "+con.getHeaderField(header)); _b>F#nD,'%
else *i@sUM?K
break; ,Z^Ca15z
} 2zz,(RA
} j:7*3@f
:.Y|I[\E%
dVa!.q_3
public void splitterStop() DhZ:#mM{
{ \Ke8W,)ew
bStop = true; ?N:B
} rvW!7-R
+}P%HH]E/p
<"<Mbbp
} 85'nXYN{d
Y=r!2u6r~
djWcbC=g_
/* )D;*DUtMVm
**FileAccess.java ~e{H#*f&1/
*//文件访问(定位，写) =/[ltUKs:a
package NetFox; JjQ8|En
import java.io.*; T'E] i!$
n|WfaJQZ
UEzsDJu
public class FileAccessI implements Serializable{ C;9t">prk
ny)]GvxI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WE0}$P:
RandomAccessFile oSavedFile; t#Th9G]1
long nPos; 98GlhogWt
%;7.9%
k}GjD2m
public FileAccessI() throws IOException Y,C=@t@_
{ Q $]YD pCM
this("",0); /#f^n]v
} {3LA%xO
_pW_G1U
%`e`g ^
public FileAccessI(String sName,long nPos) throws IOException Mi]I:ka
{ (?vK_{
oSavedFile = new RandomAccessFile(sName,"rw"); 8!&nKy<Y
this.nPos = nPos; $xT1 1 ^
oSavedFile.seek(nPos); D|l,08n"?
} [& ^RP,N~
/be=u@KV
n#4Gv|{XMD
public synchronized int write(byte[] b,int nStart,int nLen) I.1D*!tz
{ w]nX?S8
int n = -1; Z&Ue|Z4Qt
try{ +c--&tBo
oSavedFile.write(b,nStart,nLen); iwU[6A
n = nLen; =Q-k'=6\
} );Z]SGd
catch(IOException e) 2:Q(Gl`<l
{ ;\qXbL7
e.printStackTrace (); P>(P2~$Y"
} *:g_'K"+
VevNG*
Fi4UaJ3K
return n; rFey4zzz
} A?8\Y{FQ
*t(4 $
wO7t!35
} 4/'N|c.
:'}@Al9=>
'Dath>Y=
/* }$&xTW_
**SiteInfoBean.java 6V1:qp/6
*/ G(/DtY]
package NetFox; %?9Ok
z\TLsx
^z~~VBv
public class SiteInfoBean { +6l]]*H
H=p`T+
/1d<P! H
private String sSiteURL; //Site's URL "UG K8x
private String sFilePath; //Saved File's Path &J$##B
private String sFileName; //Saved File's Name (u&`Ij9
private int nSplitter; //Count of Splited Downloading File e4\dpvL
W\8Ln>
Z(e^iH
public SiteInfoBean() +BL{@,zr
{//nSplitter的缺省值为5 $ J1f.YE
//default value of nSplitter is 5 -:<lkq&/
this("","","",5); [|RjHGf
} )K;]y-Us[
kccWoU,
#H~_K}Ks
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l+'F_a
{ xq[Yg15d%
sSiteURL= sURL; fPqr6OYz
sFilePath = sPath; wvN`R
sFileName = sName; <{Q'&T
this.nSplitter = nSpiltter; W2]TRO
@0NJ{
|yKud
} &;c>O
1/;o
vWjnI*6T#
public String getSSiteURL() X%}nFgqQ
{ QR0(,e$Dl
return sSiteURL; h/)_) r.x
} |^a;77nE_^
_mJG5(|
o6a0'vU><
public void setSSiteURL(String value) W\cjdd
{ }^%xvmQ\]
sSiteURL = value; taWqSq!
} I:l01W;
5l{Ts04k%
Kct@87z
public String getSFilePath() !wE}(0BTx
{ KpHw-6"
return sFilePath; BPv>$ m+.
} cn`iX(ZgR
!%)]56(
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public void setSFilePath(String value) HrM$NRhu
{ Vzg=@A#
sFilePath = value; N|usFqCNk^
} N( Oyi
#7G*GbKY
J G$Z.s
public String getSFileName() =9wy/c$
{ r^fe4b
return sFileName; %,P>%'0
} *ZrSiIPP
!t#F/C
xHA0gZf
public void setSFileName(String value) Fc6iQ
{ 'b&yrBFD
sFileName = value; zM#sOg
} H t(n%;<
j5$GFi\kB
o\VUD
public int getNSplitter() (s<s@`
{ ;C.S3}
return nSplitter; i^msjA
} ac{?+]8}
?)D^~/ A
b KtD"JG\
public void setNSplitter(int nCount) S\i@s_
{ TrS8h^C
nSplitter = nCount; LeOP;#
} zp}eLm:=d
} }H> ^o9
>l']H*&B<
4T6 {Y
/* IxZb$h[
**Utility.java V)ig)(CT
*/ Yf@e=:
package NetFox; L{-LX=G^
u\yVR$pQ
2,q}Nq
public class Utility { \3f&7wU
]`g@UtD9`
&ANP`=
public Utility() )kXhtjOl|
{ dt@P>rel
2Os1C}m
q?qC
} H,unpZ(
I#F!N6;
//线程睡眠 w8S!%abl1
public static void sleep(int nSecond) k <iTjI*N
{ n{*D_kM(H
try{ "*1f;+\
Thread.sleep(nSecond); {^a36i
} D,v U
catch(Exception e) "\C$
{ Yb3mP!3q8Z
e.printStackTrace (); GzXUU@p
} ^!<dgBNj
} H,3\0BKk
OJ|r6
//日志 :}8Z@H!KkY
public static void log(String sMsg) {%lXYMyu
{ W]M)Q}:Y
System.err.println(sMsg); Mips.Bx
} D"(L5jR8m@
g[RI.&?
S{pXs&4O
public static void log(int sMsg) ~c^>54
{ e}/Lk5q!
System.err.println(sMsg); Z>c3
} lGwl1,=
} RqEH|EUZ
,mhQ"\+C
R'EUV0KX>Y
/* 7w,FX.=;cv
**TestMethod.java VVH.2&`I
*/ Unj.f>U
package NetFox; voP7"Dl[
wN1niR'
|8>3`w!
public class TestMethod { dI&!e#Y
j`^$#
IG)s^bP
public TestMethod() ;c~cet4
{ ///xx/weblogic60b2_win.exe zJP6F.Ov!
try{ @k[R/,#'[t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); F<>!kK/c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dm0QcW4
SiteFileFetch fileFetch = new SiteFileFetch(bean); D]w!2k%V
fileFetch.start(); xh7cVE[UM
} ]#7zk9
catch(Exception e){e.printStackTrace ();} }bY;q-
kB?al#`
7K)6^r^
} I2nF-JzD2a
g?-lk5
|f~@8|MQP+
public static void main(String[] args) .CL^BiD.D
{ ee%fqVQ8P
new TestMethod(); I}Nd$P)>
} _ZY)M
} ?\C"YG69T
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