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)); acl<dY6
} DD$>3`
for(int i=0;i<nEndPos.length-1;i++) GVXdyi
{ G@H!D[wd
nEndPos = nStartPos[i+1]; "9s_[e
} V_SH90@)+
nEndPos[nEndPos.length-1] = nFileLength; z/{X{+Z
} h) Wp
} =Hd yra
n6%`
DRQx5fgL
//启动子线程 J|q(HpB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #; ?3kuq(
for(int i=0;i<nStartPos.length;i++) @[3c1B6K
{ S\TXx79PhC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *vaYI3{qN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ps 3)d
nStartPos,nEndPos,i); 3 39q%j$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bGWfMu=n
fileSplitterFetch.start(); hN'])[+V
} Tsg9,/vXM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )SmnLvL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KRaL+A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LQR2T5S/Q,
nEndPos = " + nFileLength); 4qie&:4j
// fileSplitterFetch[nPos.length-1].start(); F]3Y,{/V
s7Agr!>f
BNK]Os
//等待子线程结束 nzflUR{`-
//int count = 0; h+g\tYWGP
//是否结束while循环 #Lhv=0op
boolean breakWhile = false; G|g^yaq>
nQc#AFg
/WTEz\k
while(!bStop) O]u'7nO{{
{ "Q.*
write_nPos(); S!b18|o"
Utility.sleep(500); s/D)X=P1
breakWhile = true; WBE>0L
C{}_Rb'x
@V*dF|# /
for(int i=0;i<nStartPos.length;i++) q7X]kr*qx
{ OH\^j1x9I
if(!fileSplitterFetch.bDownOver) 8?+|4:#=*J
{ .Fn|Okn^gr
breakWhile = false; hk~/W}sI
break; >aVgI<
} ]b4IO4T
} $,4h\>1WP
if(breakWhile) WkTJ M
break; fM;,9
Rg?6eN
7N9NeSH
//count++; /}?7Eni
//if(count>4) @[n#-!i
// siteStop(); 9"P|Csj
} bx3Q$|M?
<gp?}Lk
XNJ4T]><
System.err.println("文件下载结束！"); t7+A!7b{
} s6bsVAO>
catch(Exception e){e.printStackTrace ();} bHwEd%f
} m^_=^z+
kU<t~+
l[}4 X/
//获得文件长度 c2npma]DZ
public long getFileSize() tq3_az ~1
{ y}odTeq
int nFileLength = -1; C ^Y\?2h1
try{ 8-2`S*
URL url = new URL(siteInfoBean.getSSiteURL()); 4V,.Oi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $GJT
httpConnection.setRequestProperty("User-Agent","NetFox"); x|6]+?l@6
wX,V:QE
vQMBJ&
int responseCode=httpConnection.getResponseCode(); `R[Hxi
if(responseCode>=400) }E 'r?N
{ bNea5u##
processErrorCode(responseCode); W:]FYC
return -2; //-2 represent access is error Ww7Ya]b.k
} 3A#Tn7
,EB}IG]
z5>I9R^q;
String sHeader; :?t~|7O:
2c9?,Le/;
]b4WfIu
for(int i=1;;i++) ?{ir$M
{ 4%(Ji
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Cx7-I0!
//Utility.log(in.readLine()); !U^{`V jp[
sHeader=httpConnection.getHeaderFieldKey(i); +hxG!o?O
if(sHeader!=null) A6&*VD
{ d#ir=+o{h
if(sHeader.equals("Content-Length")) !J`lA
{ gYKz,$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2B,O/3y
break; O*EV~{K
} /A=w`[<
} 6%v9o?:~l
else -=ZL(r 1
break; JB_fS/I
} sXIYl% d
} R?{+&r.X
catch(IOException e){e.printStackTrace ();} F/>_PH57
catch(Exception e){e.printStackTrace ();} Wlj&_~
h@:K=ggK
Zj`WRH4
Utility.log(nFileLength); :D.0\.p
=*mT{q@
~Z\:Nx
return nFileLength; =6%oW2E\
} TktH28tK
R@vcS=m7
E[H
//保存下载信息（文件指针位置） zKJ2~=
private void write_nPos() .|UQ)J?s
{ +&EXTZ@o
try{ FfoOJzf~o
output = new DataOutputStream(new FileOutputStream(tmpFile)); gAqK)@8-
output.writeInt(nStartPos.length); -3I3 X
for(int i=0;i<nStartPos.length;i++) $NXP)Lic)
{ aB9!}3@
// output.writeLong(nPos); ud1M-lY\U
output.writeLong(fileSplitterFetch.nStartPos); rO1!h%&o"
output.writeLong(fileSplitterFetch.nEndPos); 3*b5V<}'|
} [M?2axOC
output.close(); ahBqYAK9
} V$^jlWdR
catch(IOException e){e.printStackTrace ();} ]-fkmnmWX
catch(Exception e){e.printStackTrace ();} \o9 \ikR
} )9QtnM
XX6Z|Y5.
7>vm?a^D2&
//读取保存的下载信息（文件指针位置） 9Em#Ela
private void read_nPos() *XVwTW[a
{ A4K.,bZ
try{ [Kgb#L'{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |c_qq Bd
int nCount = input.readInt(); jc}G+|`
nStartPos = new long[nCount]; !vnQ;g5
nEndPos = new long[nCount]; vF$i"^;tJ;
for(int i=0;i<nStartPos.length;i++) #(8|9
{ "q@m6fs
nStartPos = input.readLong(); c OYDN[k
nEndPos = input.readLong(); Gr"CHz/
} ?1e{\XW
input.close(); ;JW_4;-
} QTV*m>D
catch(IOException e){e.printStackTrace ();} .n-#A
catch(Exception e){e.printStackTrace ();} y8Va>ul"U
} FL0uY0K
yV30x9i!2
I.2J-pu}
private void processErrorCode(int nErrorCode) eL!41_QI
{ sV^:u^
System.err.println("Error Code : " + nErrorCode); ']]d-~:
} r~w.J+W
s\ IKSoE
*7BfK(9T
//停止文件下载 k;WD[SV
public void siteStop() 4zug9kFK
{ hlTbCl
bStop = true; RaZ>.5 D
for(int i=0;i<nStartPos.length;i++) 92+8zX
fileSplitterFetch.splitterStop(); c\bL_
{pzj@b 1S
ZykMri3bi
} W:w~ M'o
} s}D>.9
//负责部分文件的抓取 ]BQYVx/
**FileSplitterFetch.java @[$_cGR7
*/ y4V:)@P
package NetFox; s0kp(t!fiu
S}m_XR]
V7ph^^sC}
import java.io.*; :Mf"
import java.net.*; $Y$9]G":
#el27"QP0
Fe+ @;
public class FileSplitterFetch extends Thread { iyskADS
s?SspuV
x3@-E
String sURL; //File URL ao(T81
long nStartPos; //File Snippet Start Position ~MpikBf
long nEndPos; //File Snippet End Position ;"3B,Yj
int nThreadID; //Thread's ID k3\N.@\
boolean bDownOver = false; //Downing is over D}-.<
boolean bStop = false; //Stop identical XQ}Zr/f6
FileAccessI fileAccessI = null; //File Access interface =;}W)V|X)S
|(7}0]BP0
xQy,1f3s+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~j0rORy]
{ 'J|2c;M\x
this.sURL = sURL; B.z$0=b
this.nStartPos = nStart; %+7]/_JO&
this.nEndPos = nEnd; @KG0QHyiU
nThreadID = id; 0p.bmQSH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s-i|P
} 0mw1CUx9K
yPyu)
gcLz}84
public void run() (IJNBJb
{ E?m~DYnU
while(nStartPos < nEndPos && !bStop) q76POytV|
{ 'CLZ7pV
qnm_#!&uHT
(8nv&|
try{ h}b:-a
URL url = new URL(sURL); xNz(LZ.c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #-hO\ QdC
httpConnection.setRequestProperty("User-Agent","NetFox"); v=`yfCX-qX
String sProperty = "bytes="+nStartPos+"-"; x2"iZzQlD
httpConnection.setRequestProperty("RANGE",sProperty); LQ0/oYmNc
Utility.log(sProperty); H=dIZ
?^|`A}q#
18g_v"6o
InputStream input = httpConnection.getInputStream(); Hl*vS
//logResponseHead(httpConnection); Cu"Cpt[
.UyE|t4
HL)!p8UHJ
byte[] b = new byte[1024]; DA=!AK>
int nRead; ~lj~]j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0D-`>_
{ ]`^! ]Ql
nStartPos += fileAccessI.write(b,0,nRead); Obdn#Wm=
//if(nThreadID == 1) $JE,u'JQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !(sn9z#
} e3~MU6
a6p0_-MF
-@To<<`n
Utility.log("Thread " + nThreadID + " is over!"); qY_qS=H^
bDownOver = true; Vns3859$8
//nPos = fileAccessI.write (b,0,nRead); K!|eN_1A
} VK}4<u
catch(Exception e){e.printStackTrace ();} 8&<:(mAP
} (Wzp sDte
} ju~$FNt8R
Gvb2>ZN
XN<SKW(H3
//打印回应的头信息 K+g[E<x\=
public void logResponseHead(HttpURLConnection con) X-pbSq~5
{ [g}Cve#i
for(int i=1;;i++) _0H oJ
{ UBvp32p
String header=con.getHeaderFieldKey(i); i,Ct AbMx
if(header!=null) uo F.f$%"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^$c#L1 C
Utility.log(header+" : "+con.getHeaderField(header)); 16NHzAQ
else ?HEqv$n
break; T^bAO-d#
} rb?7i&-
} <O#&D|EMd|
^BsT>VSH6
*dBy<dIy
public void splitterStop() .35(MFvq!
{ d\z6Ob"t
bStop = true; =j7Du[?Vu
} dab]>% M
]>3Y~KH(
)|gw5N4;
} 3o.x<G(
M!&Hn,22
{UNH?2
/* MBLZ:A| C
**FileAccess.java xJq|,":gj
*//文件访问(定位，写) q8 v iC|
package NetFox; rxCzPF
import java.io.*; N:j7J
:;?$5h*|`
js$R^P
public class FileAccessI implements Serializable{ (qn=BPI
~(kEGEF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 osV6=
RandomAccessFile oSavedFile; J,W<ha*
long nPos; +{UY9_~\3
"ubp`7%67
#~0Nk6*u
public FileAccessI() throws IOException J}|X
{ \C~X_/sg
this("",0); CS^6$VL7e
} ;0DoZ
tBo\R?YRs
D(b01EQ;d
public FileAccessI(String sName,long nPos) throws IOException r. 82RoG?G
{ E@}F^0c
oSavedFile = new RandomAccessFile(sName,"rw"); ?Uql30A
this.nPos = nPos; l4C{LZ
oSavedFile.seek(nPos); "t|)Kl
} dX(JV' 18A
+p u[JHF
{3Inj8a=?A
public synchronized int write(byte[] b,int nStart,int nLen) 1U\ap{z@
{ ]#0 (
int n = -1; +eVYy_bL-
try{ 1tuvJ+`{
oSavedFile.write(b,nStart,nLen); bWSN]]e1#
n = nLen; 8SRR)O[)}
} n 0!8)Sth
catch(IOException e) 5es t
{ W"\~O"a
e.printStackTrace (); IjI'Hx
} !do`OEQKR
KEAXDF&#
dx%z9[8~{.
return n; 4o>y9
} Vl.,e1)6
:Cq73:1\B
NuZ2,<~9
} *85N_+Wv!
hSehJjEoM
:{u`qi
/* |q`NJ
**SiteInfoBean.java ,dC.|P' `
*/ x $uhkP
package NetFox; 7# AIX],
=D<0&M9C
Ai/X*y:[?
public class SiteInfoBean { C% -Tw]T$_
b6k`R4S3
o78u>Oy
private String sSiteURL; //Site's URL sn"((BsO<
private String sFilePath; //Saved File's Path Ny^ 1#R
private String sFileName; //Saved File's Name !73y(Y%TE
private int nSplitter; //Count of Splited Downloading File *g5bdQ:Av~
&ALnE:F
hHJiGVJ=V
public SiteInfoBean() TzL|{9
{//nSplitter的缺省值为5 0O3O^ 0
//default value of nSplitter is 5 XgxE M1(
this("","","",5); 2w|5SK_
} n%E,[JT
/HIyQW\Ki-
%.Y5%TyP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9f~qD&~
{ ~J\qkQ
sSiteURL= sURL; _8G w Mj
sFilePath = sPath; bBIh}aDN
sFileName = sName; G'|ql5Zw
this.nSplitter = nSpiltter; ^\}MG!l
W3:j Z:
aoy Be|H~=
} {4_s:+v0
Avx`
i'fw>-0
public String getSSiteURL() M CC4'
{ 3.W[]zH/u
return sSiteURL; @CNJpQ ujn
} pg{VKrT`
- 2)k!5X=
pRQ7rT',v
public void setSSiteURL(String value) TV{GHB!p"
{ BTAbDyH5
sSiteURL = value; 99yWUC,
} 3IxC@QR
t/|0"\ p
gIo\^ktW
public String getSFilePath() aM5]cc%
{ WI\a
return sFilePath; @$ 7 GrT
} @=kgK[t 9
ky2]%cw
?:r?K|Ku
public void setSFilePath(String value) 21TR_0g&<
{ u X,n[u
sFilePath = value; L{/% "2>
} O Z ./suR)
jNj;#C)
UJO3Yn
public String getSFileName() etX@z'H
{ /8;m.J>bf
return sFileName; /&Q{B f
} TcZ.5Oe6h#
>pu4G+M
/3s&??{tv
public void setSFileName(String value) T0 K!Msz
{ 2^[dy>[y0
sFileName = value; tz;3
} 1ksFxpE
UZ<K'H,q
;JxL>K(
public int getNSplitter() "_/ih1z]
{ HH*y$
return nSplitter; fd[N]I3
} )tG. 9"<
Q`F1t
jPSVVOG
public void setNSplitter(int nCount) \2@J^O1,
{ .wNXvnWr
nSplitter = nCount; pU_3Z3CeE
} `cp\UH@
} +b 6R
_?-oPb
(MLcA\LJ
/* 6Vnq|;W3Zv
**Utility.java [ar0{MPYd
*/ .B]l@E-u
package NetFox; "t^v;?4
W>#yXg9
gqS9{K(f
public class Utility { 0+SDFh
tWn dAM(U7
nI6gd%C
public Utility() +q&Hj|;8r
{ SnE^\I^O
?^voA.Bv<
d,GOP_N8I
} "3^tVX%$\[
[wQ48\^
//线程睡眠 =}Tm8b0
public static void sleep(int nSecond) sD3ZZcy|=
{ X&9:^$m
try{ v+LJx
Thread.sleep(nSecond); (;#c[eKy
} 8>YF}\D V
catch(Exception e) 1<ag=D`F_"
{ ^+x?@$rq
e.printStackTrace (); ^fsMfB
} * zp tbZ
} d-b04Q7DQ
K/W=r
//日志 ^;EhKG
public static void log(String sMsg) $Ivjcs:
{ 8m") )i-
System.err.println(sMsg); %jtUbBN
} w0!$ow.l
BwT[SI<Sg
@HS*%N"*
public static void log(int sMsg) *73gp
{ c'2/C5
System.err.println(sMsg); ujV{AF`JfB
} N,TV?Q5l7
} ;TL.QN/l
,4'gj0
H*0Y_H=
/* 9rEBq&
**TestMethod.java 6U{A6hH]
*/ 2j+w5KvU
package NetFox; C@XS
}xsO^K
vIpL8B86a
public class TestMethod { 2|;|C8C
ZPZh6^cc
os5$(
public TestMethod() Vg'R=+Wb
{ ///xx/weblogic60b2_win.exe &Ym):pc
try{ m|q,ixg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V}V->j*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vK!`#W`X
SiteFileFetch fileFetch = new SiteFileFetch(bean); necY/&Ld-
fileFetch.start(); 2iNLm6"
} W{;Qi&^ca
catch(Exception e){e.printStackTrace ();} (p2`ofj
E`TZ:W]r,
@6UtnX'd
} a/ Ac^!(
ko@ej^
L"ho|v9:
public static void main(String[] args) `N\ ^JAGW
{ :9QU\{2
new TestMethod(); pyhXET '
} |mtW)
} ZxvH1qx8
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