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)); vrvi] Y8
} a5w E{K
for(int i=0;i<nEndPos.length-1;i++) kpQN>XV#
{ OE}c$!@
nEndPos = nStartPos[i+1]; ,wyEo>>4)
} wDBU+Z
nEndPos[nEndPos.length-1] = nFileLength; m?;/H
} Q7mikg=1-
} ZA'0q
-KqMSf&9
'loko#6
//启动子线程 /c7jL4oD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (^<skx>
for(int i=0;i<nStartPos.length;i++) =#&+w[4?&.
{ N)KN!!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kn&BGYt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N[yS heT
nStartPos,nEndPos,i); Qv8 =CnuOT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W{ZJ^QAq/
fileSplitterFetch.start(); )E6E}
} ^Q!A4qOQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &u(pBr8B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8Qkwg]X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OY!WEP$F-C
nEndPos = " + nFileLength); JbXi|OS/
// fileSplitterFetch[nPos.length-1].start(); F C=N}5u
9*r l7
<DEu]-'>
//等待子线程结束 u|Ng>lU
//int count = 0; fvA167\
//是否结束while循环 \GGyz{i
boolean breakWhile = false; W!* P
;9vY5CxzC
i3$pqNe
while(!bStop) @CC 6`D
{ Y{X%C\
write_nPos(); _) UnHp_^
Utility.sleep(500); un)PW&~E
breakWhile = true; UGoB7TEfn
h6;zAM}
W"tGCnd
for(int i=0;i<nStartPos.length;i++) m;>:mwU
{ &NI\<C7_Gw
if(!fileSplitterFetch.bDownOver) d"lk"R
{ +zl[C
breakWhile = false; g$qM}#s0}
break; q3GkfgY
} Zk31|dL
} ~/2OK!M
if(breakWhile) 5wv7]F<
break; Y&$puiH-j
gMU%.%p2
ZRFHs>0
//count++; 1_M}Dc+J
//if(count>4) [4;G^{ bX
// siteStop(); 6DC+8I<
} =pnQ?2Og
1buO&q!vn
YuoIhT
System.err.println("文件下载结束！"); `9acR>00$
} <2OXXQ1
catch(Exception e){e.printStackTrace ();} o ethO
} RE08\gNIt
[|(=15;
C)%qs]
//获得文件长度 s&\krW&
public long getFileSize() Qm*XWo
{ fC$@m_-KD
int nFileLength = -1; ]q&NO(:kbq
try{ lLU8eHf\
URL url = new URL(siteInfoBean.getSSiteURL()); 5>~D3?IAd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?Q"1zcX
httpConnection.setRequestProperty("User-Agent","NetFox"); ?0lz!Nq'S
9H+Q/Q*-a
Iq 0ew
int responseCode=httpConnection.getResponseCode(); 1*trtb4F
if(responseCode>=400) g3(LDqB'.
{ ^^*Ia'9
processErrorCode(responseCode); ZM[Z9/S8
return -2; //-2 represent access is error ciFqj3JS
} r5NH*\Q
}$(\,SzW
Fj"/jdM
String sHeader; pfFHuS~
|ZOdfr4uW
;f)AM}~^Q
for(int i=1;;i++) (,cG+3r]
{ C3(h j
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :Vw{ lB
//Utility.log(in.readLine()); o3h>)4
sHeader=httpConnection.getHeaderFieldKey(i); Q2* ~9QkU
if(sHeader!=null) \[ 4y
{ =uR3|U(.|u
if(sHeader.equals("Content-Length")) (]zi;
{ -oB=7+g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4`")aM
break; S,vdd7Y
} rCb#E}
} 4^:$|\?]
else (ki= s+W-
break; 0!tuUn
} YoWXHg!U
} /NxuNi;5
catch(IOException e){e.printStackTrace ();} "|V}[ 2
catch(Exception e){e.printStackTrace ();} 8O[l[5u&
aS~~*UHW
[*@ +
Utility.log(nFileLength); eDvh3Y<D
2HF`}H)H
Z_[L5B]Gwd
return nFileLength; !-ZY_
} |f(*R_R
vb}c)w dp?
dEW= V"W
//保存下载信息（文件指针位置） > }kZXeR|
private void write_nPos() p8Z;QH*
{ #L57d
try{ &2I8!Ia
output = new DataOutputStream(new FileOutputStream(tmpFile)); =r3g:j/>q
output.writeInt(nStartPos.length); =y`-:j\
for(int i=0;i<nStartPos.length;i++) 6;;2e> e
{ :39arq
// output.writeLong(nPos); vJS}_j]_@
output.writeLong(fileSplitterFetch.nStartPos); oe!4ng[
output.writeLong(fileSplitterFetch.nEndPos); A8Km8"
} }c>vk
output.close(); Hx!eCTO:*
} 7U2B=]<e-
catch(IOException e){e.printStackTrace ();} |I{3~+E h
catch(Exception e){e.printStackTrace ();} {CNJlr@z
} '%o^#gJp
6?[SlPPE1
,LDL%<7t
//读取保存的下载信息（文件指针位置） @Bn4ZFB@
private void read_nPos() m;L3c(r.
{ 7xYz9r)w`
try{ *kcc]*6@s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6~x a^3G:
int nCount = input.readInt(); tD4-Llj6
nStartPos = new long[nCount]; I&<'A[vHl
nEndPos = new long[nCount]; 1aUg({
for(int i=0;i<nStartPos.length;i++) b~@+6?
{ +@*>N;$
nStartPos = input.readLong(); ]'$:Y
nEndPos = input.readLong(); 0G2Y_A&e**
} Nbv b_
input.close(); J6"GHbsO
} .tQ(q=#
catch(IOException e){e.printStackTrace ();} COmu.'%*
catch(Exception e){e.printStackTrace ();} ^YB2E*
} JAT%s %UC
@AK&R~<
@]p{%"$
private void processErrorCode(int nErrorCode) =K}T; c
{ PZlPC#E-
System.err.println("Error Code : " + nErrorCode); bm4Bq>*=U
} MU\Pggs
#)]/wqPoW
mIqm/5
//停止文件下载 '?g&);4)k-
public void siteStop() I5`>XfO)
{ Wh~,?}laj
bStop = true; 5)5yH bS
for(int i=0;i<nStartPos.length;i++) 8si{|*;hL
fileSplitterFetch.splitterStop(); -Q&@P3x
S4-jFD)U
t)rPXvx}!
} 0WYu5|
} TQ0ZBhd
//负责部分文件的抓取 5HE5$S
**FileSplitterFetch.java 69apTx
*/ rS8\Vf]F
package NetFox; fNfa.0s
.w'b%M
-=5~-72~
import java.io.*; 6NHP/bj<1V
import java.net.*; a'.7)f[g}
\fuz`fK:
2)T;N`tNw
public class FileSplitterFetch extends Thread { b?qV~Dgk`
]@#wR
o>bi~(H
String sURL; //File URL LsaX HI/?b
long nStartPos; //File Snippet Start Position :8==Bu
long nEndPos; //File Snippet End Position >yHtGIHe-
int nThreadID; //Thread's ID 5SmJ'zFO
boolean bDownOver = false; //Downing is over *ZFF$0}
boolean bStop = false; //Stop identical J9DI(`
FileAccessI fileAccessI = null; //File Access interface {9.UeVz
3IB9-wG
S8v?H|rm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p .P#S
{ &m GU
this.sURL = sURL; x'..j5
this.nStartPos = nStart; x%HxM~&
this.nEndPos = nEnd; ]<L~f~vU
nThreadID = id; g j]8/~lr
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5\w*W6y
} 67Qu<9}<-
78~/1-
$5&~gHc,
public void run() jb{9W7;RL
{ b{{ H@LTW
while(nStartPos < nEndPos && !bStop) 56.JBBZZ
{ P1B=fgT
>VQLC&u(
svb7-.!
try{ u86PTp+
URL url = new URL(sURL); r>TOJVT&]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <>Dw8?O
httpConnection.setRequestProperty("User-Agent","NetFox"); Z P6p>?DQ
String sProperty = "bytes="+nStartPos+"-"; x(R;xB
httpConnection.setRequestProperty("RANGE",sProperty); f?ibyoXL
Utility.log(sProperty); 8oXp8CC
qswC>Gi
z@pa;_
InputStream input = httpConnection.getInputStream(); ZkQ6~cM
//logResponseHead(httpConnection); 1s(]@gt
!.q9:|oc
R[S1<m;
byte[] b = new byte[1024]; yXv@yn
int nRead; yNn=r;FZQ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) EltCtfm`
{ ,d&3IhYhD
nStartPos += fileAccessI.write(b,0,nRead); S<*IoZ?T
//if(nThreadID == 1) ,Z _@]D@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3S2Alx!6
} #7}M\\$M
ZH8w^}
(_CvN=A
Utility.log("Thread " + nThreadID + " is over!"); ^FBu|eAkE
bDownOver = true; Kg2Du'WQ^
//nPos = fileAccessI.write (b,0,nRead); c00rq ~<K
} vCSC:
catch(Exception e){e.printStackTrace ();} 5U4V_*V
} 9y;}B y
} NA'45}fQ
NH}o`x/
_>kc:
//打印回应的头信息 g,M-[o=Fk
public void logResponseHead(HttpURLConnection con) d;wq@e
{ js"5{w&
for(int i=1;;i++) )oz2V9X{
{ &GJVFr~z
String header=con.getHeaderFieldKey(i); F kf4R5Y?
if(header!=null) d|7LCW+HW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &FT`z"^
Utility.log(header+" : "+con.getHeaderField(header)); VP^Yf_
else Zf<T`'_d
break; =>tkc/aa
} b7I0R;Zj
} J5HK1
!6RDq`
{=mGXd`x?l
public void splitterStop() i20y\V os?
{ vt*
bStop = true; ~ss6yQ$
} ruB D ^-
]&q<O0^'
-WF((s;<#
} CMOyK^(e
CM++:YvJ
lqJ92vi6Q
/* yt5<J-m
**FileAccess.java eI2HTFyT
*//文件访问(定位，写) 9X;*GC;d
package NetFox; Ng*-Bw)p]
import java.io.*; LD5`9-
{"{]S12N
\y(3b#
public class FileAccessI implements Serializable{ 7(h@5
YW/V}C'>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3Wv^{|^
RandomAccessFile oSavedFile; n5.sx|bI?
long nPos; xsJXf @
6vE#$(n#a&
DwGM+)!
public FileAccessI() throws IOException ;R#RdUFH
{ Rk#'^}
this("",0); y2s(]#8
} j=M%*`@
BSgT 6K
S\:+5}
public FileAccessI(String sName,long nPos) throws IOException 1 Ga3[g
{ R5^6Kwu
oSavedFile = new RandomAccessFile(sName,"rw"); E&y)`>Nq{
this.nPos = nPos; Xy=ETV%
oSavedFile.seek(nPos); ``:[Jr&
} 9wldd*r
GPhhg
l7^^MnkC
public synchronized int write(byte[] b,int nStart,int nLen) B;e<.M)e
{ Q8m%mJz~]
int n = -1; j8[U}~*^
try{ 2-8Dc4H]r
oSavedFile.write(b,nStart,nLen); 0NZ'(qf~9
n = nLen; >uq0}HB$a
} \OFmd!Cz
catch(IOException e) zm5PlG
{ ,-E'059
e.printStackTrace (); Komdz/g
} }s<;YC
?z l<"u
-wV2 79^b
return n; ov,s]g83
} h`N2M,
xi "3NF%=
z|%Pi J,
} X5[t6q!
{x,)OgK!{
3Q=\W<Wu
/* .9B@w+=6
**SiteInfoBean.java 0,DrVGa
*/ ^IuhHP
package NetFox; a?r$E.W'&
r2.w4RMFua
klFS3G
public class SiteInfoBean { sV{\IgH/x
"D_:`@V(
59l9_yFJ
private String sSiteURL; //Site's URL v:/!OvLe
private String sFilePath; //Saved File's Path X coPkW
private String sFileName; //Saved File's Name 2!B|w8ar
private int nSplitter; //Count of Splited Downloading File Q}lCQK/g
P<vU!`x%q
@- |G_BZ
public SiteInfoBean() t7x<=rW7u
{//nSplitter的缺省值为5 a}FyJp
//default value of nSplitter is 5 6#CswSpS
this("","","",5); #vyf*jPr
} cw 2!V@
54>0Dv??H
O]=jI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1aRTvaGo
{ W& 0R/y7
sSiteURL= sURL; +O 7( >a
sFilePath = sPath; ;#v3C;
sFileName = sName; +39uKOrZ
this.nSplitter = nSpiltter; zM&ro,W
:AztHf?X
rY^uOrR>j*
} w$f_z*/
HSG Ln906
H6 x
public String getSSiteURL() T&pCLvkz
{ oydP}X
return sSiteURL; =&UE67eK,
} JnK<:]LcK
^"?a)KC
{q8|/{;
public void setSSiteURL(String value) :+jg311}
{ `&q+ f+z
sSiteURL = value; {u1|`=;
} Lr*PbjQDIY
:K2 X~Ty
$#D#ezvxe
public String getSFilePath() ~"`e9Im
{ hjg1By(
return sFilePath; .p e3L7g
} Q34u>VkdQI
gF)-Ci
`f~bnL
public void setSFilePath(String value) j`.&4.7+
{ # f-hI
sFilePath = value; G2I%^.s
} 3R%JmLM+R9
w(ZZTVW-
R)Mkt8v
public String getSFileName() O[MFp
{ RNB&!NC
return sFileName; X(BxC<!D.
} 61kSCu
BI)C\D3[
C;JW\J~W
public void setSFileName(String value) #btf|\D
{ T>nH=
sFileName = value; _dk[k@5W{'
} gw,K*ph}q
>^g2Tg:
QEt"T7a[/
public int getNSplitter() (jU_lsG
{ UwS7B~
return nSplitter; Iga+8k
} Y2l;NSWU
8o|C43Q_
;AOLbmb)H4
public void setNSplitter(int nCount) =bD.5,F)
{ ya~;Of5
nSplitter = nCount; nsi?.c&0!
} OjlX<y.
} E%v0@
[nVBnB
sv%E5@
/* 5<PNl~0
**Utility.java Sq,>^|v4&e
*/ #b428-
package NetFox; 1ds4C:M+<
4pT^*
MFa/%O_*
public class Utility { zC)JOykI%
oc,I,v
l([aKm#
public Utility() D )`(b
{ &\6},JN
aeN #<M&$<
9Xg7=(#
} FvVC 2Z
F5x*#/af
//线程睡眠 4bL *7bA
public static void sleep(int nSecond) *\'t$se+
{ T$u'+* Xx
try{ xf;>o$oN0P
Thread.sleep(nSecond); UJqh~s
} IowXVdm@6
catch(Exception e) +=9iq3<yfS
{ <\$"U5"`
e.printStackTrace (); 1K/ :
} 1HNP@9ga
} F!hjtIkPj
#3_g8ni5X
//日志 9VTAs:0D=
public static void log(String sMsg) EQ^]W-gN
{ s/hWhaS<
System.err.println(sMsg); l+2NA4s
} P]^OSPRg
!Q~>)$Cf^
b6k_u9m^E
public static void log(int sMsg) @R`6jS_gK
{ D ON.)F
System.err.println(sMsg); E@k'uyIu
} XTX/vbge3m
} y{3+Un
R3og]=uFzm
AC <2.i_
/* U{ 0~&
**TestMethod.java a"YVr'|
*/ 9jf9u0
package NetFox; V]J"v#!{
D<FQVdP
WynTU?
public class TestMethod { .^=I&X/P
u(1m#xr8$
dDl+
public TestMethod() 0|-}>>qb\
{ ///xx/weblogic60b2_win.exe n[!QrEeR},
try{ 4t =Kt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {G vGV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lq53 xT
SiteFileFetch fileFetch = new SiteFileFetch(bean); &D[M<7T
fileFetch.start(); hY{4_ie=8
} Dx /w&v
catch(Exception e){e.printStackTrace ();} ws`r\k]3J
NvIg,@}
yc]_?S>9
} p2l@6\m\
)vOBF5
+-;v+{
public static void main(String[] args) 5|eX@?QF58
{ w)S 4Xi=
new TestMethod(); dL4VcUS.
} 0B9FPpx?:
} 3O*iv{-&
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