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)); q86}'dFw{
} z$}9f*W}B
for(int i=0;i<nEndPos.length-1;i++) :ir3u
{ YTmHht{j#
nEndPos = nStartPos[i+1]; \%bJXTK&W
} @Tq-3Um
nEndPos[nEndPos.length-1] = nFileLength; Lj#xZ!mQS
} GvgTbCxnN
} r}^1dO
3A[<LnKR^E
N{&Lo}6F
//启动子线程 x4g/ok
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9wGsHf8]
for(int i=0;i<nStartPos.length;i++) X%&7-PO
{ S w%6-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V=th-o3[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FE^/us7r
nStartPos,nEndPos,i); GG<0k\RN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U{bv|vF
fileSplitterFetch.start(); &7>]# *
} *| W*Mu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G!=(^G@J;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s3yGL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Skr0WQ
nEndPos = " + nFileLength); }YBuS3{
// fileSplitterFetch[nPos.length-1].start(); -sZ'<(3
Fw{#4
dT% eq7=
//等待子线程结束 BBGub?(dR
//int count = 0; +F60_O `
//是否结束while循环 Hm!"%
boolean breakWhile = false; ;~djbo0,X
Uf]$I`T#
nTD%i~t~o
while(!bStop) 2p#d
{ &z5?]`ALu
write_nPos(); 1%R${Qhr
Utility.sleep(500); ebNRZJ?C,
breakWhile = true; m[Ihte->
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MN5}}@
for(int i=0;i<nStartPos.length;i++) k\;D;e{
{ mAGD qz>f
if(!fileSplitterFetch.bDownOver) lo'#dpt<
{ Mp!1xx
breakWhile = false; aXQAm$/ >
break; '0)`.
} 3)LS#=
} a9.255
if(breakWhile) [g<gu~
break; ;<''oY
rP2h9Cb
X[H.t$w5A
//count++; 7-n HPDp'
//if(count>4) V9}\0joM
// siteStop(); dY0W=,X$7T
} dmv0hof
?E V^H-rr
@lWNSf
System.err.println("文件下载结束！"); x|Pz24yP9
} IemhHf ^l
catch(Exception e){e.printStackTrace ();} 4q7H
} 4|I;z
Ja4M@z
&v1E)/q{Z
//获得文件长度 }`H{;A h
public long getFileSize() NS`hXf
{ Bw!J!cCj
int nFileLength = -1; &Ejhw3Nw
try{ bpU>(j
URL url = new URL(siteInfoBean.getSSiteURL()); cZF|oZ6<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @4Bl&(3S
httpConnection.setRequestProperty("User-Agent","NetFox"); Xf#;`*5
:E|Jqi\
"nfi:A1
int responseCode=httpConnection.getResponseCode(); ,X:3w3nr^
if(responseCode>=400) x7^VU5w#
{ SSla^,MHef
processErrorCode(responseCode); 2dKt}o>
return -2; //-2 represent access is error ^z{Xd|{"
} l59 N0G
m-tn|m!J
btnD+O66<
String sHeader; \),f?f-m
u$zRm(!RB
:=+YZ|&j
for(int i=1;;i++) a3w6&e`
{ K;rgLj0m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yS4VgP'W
//Utility.log(in.readLine()); i M MKA0JM
sHeader=httpConnection.getHeaderFieldKey(i); e1JHN
if(sHeader!=null) lg2I|Z6DH
{ [\<#iRcP
if(sHeader.equals("Content-Length")) 8au Gz ,"
{ [_3&
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zos.WS#
break; 0QPY+6
} `+vQ5l$;L
} *,:2O&P
else RFFbS{U*
break; g@s`PBF7`
} ,YBO}l
} )p;t '*]
catch(IOException e){e.printStackTrace ();} 8EdaqF
catch(Exception e){e.printStackTrace ();} +e*C`uP!
J?dz>3Rhx9
3)o>sp)Ji$
Utility.log(nFileLength); [.xc`CF
3]lq#p:
RdyKd_0`Q
return nFileLength; }|) N5bGQe
} 4ME$Z>eN
<*^|Aj|#
kb"Fw:0
//保存下载信息（文件指针位置） s?S e]?i
private void write_nPos() F@Wi[K
{ ?q Q.Wj6Mj
try{ "[fPzIP9
output = new DataOutputStream(new FileOutputStream(tmpFile)); fr04nl
output.writeInt(nStartPos.length); ;vPFRiFK
for(int i=0;i<nStartPos.length;i++) K re*~ "
{ eFf9T@
// output.writeLong(nPos); SEg{Gso9b
output.writeLong(fileSplitterFetch.nStartPos); we!w5./Xm
output.writeLong(fileSplitterFetch.nEndPos); T]1.":
} ujBm"p_|
output.close(); F !OD*]
} `^on`"\{u
catch(IOException e){e.printStackTrace ();} eY?OUS
catch(Exception e){e.printStackTrace ();} ZBx,'ph}4
} F 2zUz[
)G, S7A
kCz2uG)l
//读取保存的下载信息（文件指针位置） /y4A?*w6
private void read_nPos() 6(htpT%J
{ CKe72OC
try{ HN/YuP03[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); NYg&8s.
int nCount = input.readInt(); m8F \ESL
nStartPos = new long[nCount]; |x&4vHXR0
nEndPos = new long[nCount]; MNTVG&h
for(int i=0;i<nStartPos.length;i++) _7;G$\^&.
{ LX&O"YY
nStartPos = input.readLong(); {6Nbar@3
nEndPos = input.readLong(); L7GNcV]c
} 0LzS #J+
input.close(); vR5X
} NM),2%<
catch(IOException e){e.printStackTrace ();} hSAI G
catch(Exception e){e.printStackTrace ();} s[UV(::E
} hR2 R
qM 1ZCt
aL;zN%Tw
private void processErrorCode(int nErrorCode) jpR]V86G
{ A0;{$/
System.err.println("Error Code : " + nErrorCode); fU%Ys9:wU
} yV L >Ie/
.8ikcs
^!k_"C)B
//停止文件下载 %z[=T@
public void siteStop() 1B&XM^>/
{ )>Z@')Uk:
bStop = true; Mg8ciV}\xY
for(int i=0;i<nStartPos.length;i++) ~p{YuW[e
fileSplitterFetch.splitterStop(); $I#~<bW,
Rc D5X{qS#
fwzyCbks
} Yh"9,Z&wiR
} ngd4PN>{4
//负责部分文件的抓取 #wvGS%
**FileSplitterFetch.java 7J$rA.tu
*/ ;Z"Iv
package NetFox; iGj,B =35
rAW7Zp~KK
|t3}>+"?z
import java.io.*; g}hNsU=$5~
import java.net.*; F/j ; q
qQo*:3/];
+9t{ovF?L
public class FileSplitterFetch extends Thread { YbWz!.WPe
N~`r;E
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String sURL; //File URL 8(q8}s$>
long nStartPos; //File Snippet Start Position 48J{Y3F
long nEndPos; //File Snippet End Position F2<Q~gQ;
int nThreadID; //Thread's ID 3|G~_'`RLt
boolean bDownOver = false; //Downing is over 9<P%?Q
boolean bStop = false; //Stop identical J?Q@f
FileAccessI fileAccessI = null; //File Access interface e(1{W P
wkPomTO
}lJ|nl`c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eDNY|}$}v
{ =*+f2
this.sURL = sURL; Iw#[K
this.nStartPos = nStart; > 9z-/e
this.nEndPos = nEnd; vKdS1Dn1
nThreadID = id; g?}h*~<b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~WV1t][
} k@n L(2
"OkZ [E)
DSp~k)
public void run() :c )R6=v
{ fffWvf
while(nStartPos < nEndPos && !bStop) 9M|#X1r{%{
{ U%VFr#
hmb=_W
?,hGKSC
try{ I7'v;*
URL url = new URL(sURL); KlBT9"6"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l#+@!2z
httpConnection.setRequestProperty("User-Agent","NetFox"); =R9`to|
String sProperty = "bytes="+nStartPos+"-"; ~Z#\f5yv@
httpConnection.setRequestProperty("RANGE",sProperty); d=\\ik8
Utility.log(sProperty); Ln\Gv/)
i#4E*B_-
YVz,P_\(m
InputStream input = httpConnection.getInputStream(); SST@
//logResponseHead(httpConnection); ^tjM1uaZ5(
(0?FZ.9%
2U+Fat@
byte[] b = new byte[1024]; 'q8:1i9\[
int nRead; %/s+-j@s:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0.(7R,-
{ _R ;$tG,
nStartPos += fileAccessI.write(b,0,nRead); '=K~M
//if(nThreadID == 1) ^fS_h`B
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); biQ~q$E
} R-f('[u
8N#.@\'kz.
$"Ci{iE
Utility.log("Thread " + nThreadID + " is over!"); oMq:4W,
bDownOver = true; ._'.F'd
//nPos = fileAccessI.write (b,0,nRead); ~"R;p}5"
} [,z>msEB.
catch(Exception e){e.printStackTrace ();} l]IQjjJ`
} W7T2j+]
} &&96kg3
a'my0m
Q b5vyV `
//打印回应的头信息 v}^uN+a5
public void logResponseHead(HttpURLConnection con) v?DA>
{ "!Hm.^1
for(int i=1;;i++) j(_6.zf
{ 8}Maj
String header=con.getHeaderFieldKey(i); i^}DIx{
if(header!=null) Et)j6xz/F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8..g\ZT
Utility.log(header+" : "+con.getHeaderField(header)); }.<]A
else ?U~`'^@
break; UX?S#:h
} -li;w tCS
} >+ Im:fD
Thp!X/2O`
8&#)}A}x
public void splitterStop() +/#Lm#*nu%
{ $1D>}5Ex
bStop = true; ;|Rrtf9
} ?SoRi</1
$*+UX
6bbzgULl
} nh"LdHqiDB
R&L^+?
j5 W)9HW:
/* {w9GMqq
**FileAccess.java nN[QUg
*//文件访问(定位，写) <gY.2#6C\%
package NetFox; ?NUDHUn_
import java.io.*; iN+&7#x;/
8d>>r69$pa
2wYY0=k2
public class FileAccessI implements Serializable{ hOcVxSc.
glNXamo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 { %af
RandomAccessFile oSavedFile; ;J?zD9
long nPos; mS-{AK
1jj.oa]
+"[}gss!@
public FileAccessI() throws IOException gG,gL9o
{ 'v&f
this("",0); ]y/!GFQ
} {UOR_Vt!*
=>)4>WT8A
)^Md ^\?
public FileAccessI(String sName,long nPos) throws IOException /2]=.bLwz
{ :x_;-
oSavedFile = new RandomAccessFile(sName,"rw"); 4VlQN$
this.nPos = nPos; zT _[pa)O`
oSavedFile.seek(nPos); 77zDHq=
} )Yw m_f-N
X>s'_F?
! d" i
public synchronized int write(byte[] b,int nStart,int nLen) :*E#w"$,j
{ koOp:7r
int n = -1; rY(h }z
try{ L t.Vo
oSavedFile.write(b,nStart,nLen); /AUXO]
n = nLen; `F' >NNY
} !>QD42
catch(IOException e) X!/
{ aQ.mvuMa7'
e.printStackTrace (); Qj/.x#T
} FTZaN1%`
oxgh;v*
UhF+},gU
return n; =%G<S'2'
} )|i]"8I
D7(kkr:r
Kx5VR4f`J@
} PLDp=T%
5R"(4a P
RS1c+]rr
/* Z3Y(g
**SiteInfoBean.java V|zatMHs
*/ I'T@}{h
package NetFox; uMM?s?q
"A%JT3
4"y1M=he
public class SiteInfoBean { `q(eB=6;[
-c'~0g]<
y6 _,U/9
private String sSiteURL; //Site's URL Nh/B8:035
private String sFilePath; //Saved File's Path "yc_*R(pU
private String sFileName; //Saved File's Name ^bDh[O
private int nSplitter; //Count of Splited Downloading File m%G:|`f7
*we*IhIP
YU24wTe;k
public SiteInfoBean() h(wu5G0C#u
{//nSplitter的缺省值为5 $ -n?q w
//default value of nSplitter is 5 Wk&g!FR
this("","","",5); 9Fv VM9
} lDm0O)Dh!
pz@wbu=($4
n{v[mqm^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mtg3}etA
{ >YW_}kd
sSiteURL= sURL; y72=d?]W
sFilePath = sPath; G^=C#9c.m
sFileName = sName; q+/7v9
this.nSplitter = nSpiltter; [qGj*`@C
lZ` CFZR0
a jyuk@
} TbPTgE *
tHV81F1J
ag\xwS#i5H
public String getSSiteURL() NU?05sF
{ 12MWO_'g8
return sSiteURL; } :8{z`4H
} vpl> 5%
3BWYSJ|
y&$v@]t1
public void setSSiteURL(String value) xsIuPL#_
{ .q^+llM
sSiteURL = value; ?* %JGz_
} Gh#$[5&`
",gWO8T
tE]0 #B)D<
public String getSFilePath() MTxe5ob`$Q
{ y.'5*08S0
return sFilePath; hs m%o\
} C:WXI;*cr
+)eI8o0#
P,/=c(5\}
public void setSFilePath(String value) ndU<,{r
{ UX& ?^]
sFilePath = value; bzt(;>_8
} P5^<c\Mr,Y
C0$KpUB
*[^[!'kT&
public String getSFileName() & NO:S
{ orcPKCz|"
return sFileName; v0}R]h~>\H
} ui\yY3?
-'iV-]<
- P$mN6h
public void setSFileName(String value) ev_4!+ko
{ /T_@rm
sFileName = value; ?onTW2cG;
} {!`0i
vdLBf+Zi
o2C{V1nB
public int getNSplitter() sAG#M\A6
{ 9nrH 6]
return nSplitter; LyB &u()
} AQH\ ;L
97%S{_2m/
L6-zQztn
public void setNSplitter(int nCount) ^t'mfG|DV
{ :t36]NM
nSplitter = nCount; *Fe
} ~ojH$=K>d
} D|`I"N[<
7;T6hKWV[
JXKqQxZ[X
/* ta\CZp
**Utility.java ~T_4M
*/ /d\#|[S
package NetFox; Jbrjt/OG#I
\<bar ~
Xj^Hy"HC^~
public class Utility { CPto?=*A
O_u2V'jy9
0A}'@N@G)
public Utility() ~F ,mc.
{ -J$,W`#z
X_6h8n}i
\LQ?s)~
} 6!eI=h2P
"?<$>\@; q
//线程睡眠 N^{"k,vB-
public static void sleep(int nSecond) kDz!v?Z2+B
{ i^2yq&uT(
try{ Gidh7x
Thread.sleep(nSecond); y]5c!N %8
} *}hx9:9\B
catch(Exception e) 9 ^G.]W]
{ iIe\mV
e.printStackTrace (); #@*;Y(9Ol
} Ch~2w)HAA
} iAOm[=W
9HjtWQn
//日志 Z+qTMm
public static void log(String sMsg) +~6Nq(kV
{ 1m52vQSo3l
System.err.println(sMsg); 2,nVo^13}
} ;U02VguC
1${lHVx]
yMQZulCWE
public static void log(int sMsg) @w H+,]xE
{ VhWF(*
System.err.println(sMsg); 5V|D%t2N
} <)vjoRv
} ]%RX\~Q.4
K|n$-WDG}
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/* [M7&
**TestMethod.java [HV>4,,3"
*/ 2Op\`Ht&
package NetFox; wcdD i[E>i
w;RG*rv
\sUk71L`j
public class TestMethod { u;[*Z
zi-;7lT
$!(J4v=X
public TestMethod() y2>XLELy
{ ///xx/weblogic60b2_win.exe JwkMRO
try{ 7(q EHZEr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [%8t~zg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V8aLPJ0_
SiteFileFetch fileFetch = new SiteFileFetch(bean); UJqDZIvC
fileFetch.start(); vbDSNm#Yv
} +, SUJ|
catch(Exception e){e.printStackTrace ();} 9vAY|b^
@435K'!
4!Cu>8B
} L=7U#Q/DE
VI}.MnCa
lcv&/ A
public static void main(String[] args) RY>BP[h
{ @+9x8*~S'
new TestMethod(); yEaim~
} E!~Ok
} "1<>c/h
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