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)); Zt lS*id_
} `6~*kCj5
for(int i=0;i<nEndPos.length-1;i++) pC8(>gV<h
{ (ZShhy8g
nEndPos = nStartPos[i+1]; v^@L?{"}8
} WU<#_by g
nEndPos[nEndPos.length-1] = nFileLength; {6 #3`
} {!N4|
} <g*rTqT'
d.2b7q09
zNE!m:s
//启动子线程 W**=X\"'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LWVO%@)w
for(int i=0;i<nStartPos.length;i++) Lj~lfO
{ 7e8hnTzl8<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <(f4#BP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _'I9rGlx3
nStartPos,nEndPos,i); ~%<PEl|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jb7=1OPD_
fileSplitterFetch.start(); ]m4LY.SQ
} Phb<##OB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6:B5PJq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MO _9Yi
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dtF6IdAf
nEndPos = " + nFileLength); b%oma{I=.c
// fileSplitterFetch[nPos.length-1].start(); E32z(:7M
3M@>kIT8
z? {#/
//等待子线程结束 :+R5"my
//int count = 0; spl*[ d
//是否结束while循环 Xrz0ch
boolean breakWhile = false; %1=W#jz
I?fE=2}9
qHKZ5w
while(!bStop) wR;l"*j
{ Z(<ul<?r
write_nPos(); gIRCJ=e[b
Utility.sleep(500); ,7QnZ=F
breakWhile = true; 3R{-\ZMd
}2\"(_
yjSN;3t71
for(int i=0;i<nStartPos.length;i++) #zy%B
{ |hdh4P$+|
if(!fileSplitterFetch.bDownOver) "|Pl(HX
{ ^#=L?e
breakWhile = false; kEXcEF_9P
break; HhpP}9P;
} \;?\@vo<
} )T4L^^`
if(breakWhile) Gt1Up~\s
break; !e7vc[N
eT|_0kx1
|.S;z"v![
//count++; 1z`,*eD7
//if(count>4) D3K`b4YV
// siteStop(); <N*>9S,}
} =3T?U_u@
aQG#bh [
]u,~/Gy
System.err.println("文件下载结束！"); C{ti>'"V
} GmHsO/
catch(Exception e){e.printStackTrace ();} oF>GWstTR
} {Q-U=me\
M ?3N
j~{2fd<>
//获得文件长度 wiGwN
public long getFileSize() yjr@v!o
{ KF'M4P
int nFileLength = -1; N<{`n;
try{ 3(&.[o Z
URL url = new URL(siteInfoBean.getSSiteURL()); H|Nw)*.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M'HOw)U
httpConnection.setRequestProperty("User-Agent","NetFox"); <2Q@^
vqs~a7E-P
toWmm(7v
int responseCode=httpConnection.getResponseCode(); WAa?$"U2
if(responseCode>=400) p3S c4
{ y(dS1.5F
processErrorCode(responseCode); Wk|z\OR(
return -2; //-2 represent access is error |W <:rT
} vhHMxOZ;
'l:2R,cP
V4-=Ni]k
String sHeader; f+920/>!Z
`#f=&S?k
Z C93C7lJ
for(int i=1;;i++) 2{CSH_"Z7
{ 9yh@_~rZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v2{O67j} o
//Utility.log(in.readLine()); Wa(S20yF
sHeader=httpConnection.getHeaderFieldKey(i); [*G2wP[$
if(sHeader!=null) X W)A~wPBs
{ gp HwiFc
if(sHeader.equals("Content-Length")) Q8x{V_Pot
{ 4I*Mc%dD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !`_f\
break; wDO5Zew!
} }#8uXA
} 50&F#v%YB
else b..$5
break; ^WD$ gd
} _zh5KP[{
} \2pFFVT
catch(IOException e){e.printStackTrace ();} L_mqC(vn
catch(Exception e){e.printStackTrace ();} =LxmzQO#
gN(hv.nQ
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Utility.log(nFileLength); m;f?}z_\$
pXv[]v
YSo7~^1W"
return nFileLength; bFezTl{M
} ~ fEs!hl
Fz&ilB
SAh054/St
//保存下载信息（文件指针位置） suFOc
private void write_nPos() AJfi,rFPg
{ )V3(nZY
try{ b:Kw_Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2nkj;x{H$
output.writeInt(nStartPos.length); ACO4u<M)
for(int i=0;i<nStartPos.length;i++) *\KvcRMGUa
{ WG !t!1p
// output.writeLong(nPos); %D(prA_w
output.writeLong(fileSplitterFetch.nStartPos); ]A$^ l,
output.writeLong(fileSplitterFetch.nEndPos); 1lyOp
} ,'CWt]OS'
output.close(); o?K|[gNi
} 9jGuelwN
catch(IOException e){e.printStackTrace ();} Nu/Qa:H_{
catch(Exception e){e.printStackTrace ();} C'/M/|=Q#
} /Jf`x>eiH
s9kLB.
<nTmZ-;
//读取保存的下载信息（文件指针位置） b+].Uc
private void read_nPos() c4>sE[]
{ '$h@
try{ w2N3+Tkg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xPMyG);
int nCount = input.readInt(); R P:F<`DB|
nStartPos = new long[nCount]; (1AA;)`Kp
nEndPos = new long[nCount]; Ge:-|*F
for(int i=0;i<nStartPos.length;i++) } ndvV~*1
{ YD46Z~$
nStartPos = input.readLong(); `bZU&A(`Be
nEndPos = input.readLong(); uxC
} ]Uu(OI<)
input.close(); (Ef2 w['
} 8#]7`o
catch(IOException e){e.printStackTrace ();} 4ZJT[zi
catch(Exception e){e.printStackTrace ();} TdP{{&'9
} ~"q,<t
AIl$qPKj&
Q;XHHk
private void processErrorCode(int nErrorCode) / }XsuH
{ VyoE5o
System.err.println("Error Code : " + nErrorCode); YKe0:cWc
} $]%<r?MUb-
cl8_rt
-':"6\W
//停止文件下载 E]H
public void siteStop() c[h'`KXJf-
{ I#S~
bStop = true; ]~\SR0
for(int i=0;i<nStartPos.length;i++) yxCMl.
fileSplitterFetch.splitterStop(); k?["F%)I
^\vfos
O,=Q1*c,&
} sm2p$3v
} !#c[~erNZ
//负责部分文件的抓取 =nvAOvP{?
**FileSplitterFetch.java iM/*&O}
*/ r%y;8$/-
package NetFox; 68p\WheCal
5mna7BCEb
_b!;(~@p
import java.io.*; MdVCD^B
import java.net.*; 'HQ7 |Je
eg$5z Z
9{O2B5u1
public class FileSplitterFetch extends Thread { V#gF*]q
HzD>-f
(:.Q\!aZ1
String sURL; //File URL iHE0N6%q
long nStartPos; //File Snippet Start Position POqRHuFq
long nEndPos; //File Snippet End Position ]]J#7L#
int nThreadID; //Thread's ID 'R4>CZ%jV
boolean bDownOver = false; //Downing is over t+=12{9;f
boolean bStop = false; //Stop identical y:g7'+c
FileAccessI fileAccessI = null; //File Access interface T6h;Y
,bZ"8Z"lss
kyW6S+#-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,J~,ga~
{ tC2 )j7@
this.sURL = sURL; WFU?o[k-O
this.nStartPos = nStart; 5i!V}hE
this.nEndPos = nEnd; vp\PYg;x
nThreadID = id; pu/m8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v!<PDw2'
} M1AZ}bc0]
";wyNpb(
0Jm]f/iZ
public void run() )"(V*Z
{ c;c:Ea5
while(nStartPos < nEndPos && !bStop) x @1px&^
{ 5TXg;v#Z
gCv"9j<j
`4VO&lRm
try{ Eyr5jXt%;
URL url = new URL(sURL); 0zeUP{MQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b%Wd<N2
httpConnection.setRequestProperty("User-Agent","NetFox"); [ 3$.*
String sProperty = "bytes="+nStartPos+"-"; M*d-z
httpConnection.setRequestProperty("RANGE",sProperty); L7SEswMti
Utility.log(sProperty); )-0[ra]
q<-%L1kc1
e{,!|LhpQ
InputStream input = httpConnection.getInputStream(); "#*Nnt
//logResponseHead(httpConnection); 0-*Z<cu%l
"Jb3&qdU
|WB"=PE
byte[] b = new byte[1024]; 3H1Pp*PH
int nRead; E;9Z\?P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'eqiYY|
{ ,/~[S
nStartPos += fileAccessI.write(b,0,nRead); O[; +i
//if(nThreadID == 1) 6dF$?I&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;!'qtw"CB
} ows^W8-w
h]qT1(I
>OT\~C
Utility.log("Thread " + nThreadID + " is over!"); &kb\,mQ
bDownOver = true; mRCHrw?WG
//nPos = fileAccessI.write (b,0,nRead); F#6cF=};@
} ?p(kh^z
catch(Exception e){e.printStackTrace ();} /4yOs@#
} H\ 3M
} pP3U,n
(/'h4KS@
p:B ]Ft
//打印回应的头信息 F@9Y\. ,
public void logResponseHead(HttpURLConnection con) +Z ><
{ T0r<O_ubOA
for(int i=1;;i++) w5,6$#
{ U M@naU
String header=con.getHeaderFieldKey(i); /M:H9Z8!
if(header!=null) \4aKLr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N*f^Z#B]
Utility.log(header+" : "+con.getHeaderField(header)); L.kD,'G}>
else .?f:Nb.O
break; ^+M><jE9
} u)7*Rj^
} e[}],W
85} ii{S
3EmcYC
public void splitterStop() $:e)$Xnn-
{ x:qr\Rz
bStop = true; mY`@'
} 9Fk4|+OJ
` VwN!B:
b"t")U==
} Wk}D]o0^@
%]#VdS|N
c# xO<
/* dhW<p5
**FileAccess.java .liyC~YW
*//文件访问(定位，写) l~['[Ub0)
package NetFox; Jh?z=JY
import java.io.*; x<@kjfm5
gfm;xT/y
~0ooRUWU7
public class FileAccessI implements Serializable{ 5qRc4d'
y AOg\+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yb?{LL-uy
RandomAccessFile oSavedFile; U*qNix
long nPos; J\{$ot
um[!|g/
`NSy"6{Z
public FileAccessI() throws IOException ?q!FG(
{ zKxvN3!
this("",0); \?&Au
} bDWeU}
qm'b'!gq~
sAYV)w3u"
public FileAccessI(String sName,long nPos) throws IOException LN^UC$[tk
{ q^*6C[G B
oSavedFile = new RandomAccessFile(sName,"rw"); ~{M@?8wi
this.nPos = nPos; c#QFG1
oSavedFile.seek(nPos); N_G4_12(
} ax_YKJ5#P
~@Kf2dHes
[(|v`qMv/g
public synchronized int write(byte[] b,int nStart,int nLen) ],[)uTZc
{ Obo_YE
int n = -1; 94{)"w]
try{ s4$X
oSavedFile.write(b,nStart,nLen); T4r5s
n = nLen; :}9j^}"c3
} sx5r(0Z
catch(IOException e) kXwi{P3D$
{ =IHje;s
e.printStackTrace (); 3wC R|ab}
} hD q2-X}
+.@c{5J<
ia4k:\
return n; b/<mRQ{
} R#qI(V
eN/G i<
'7tBvVO_
} 73 V"s
|pW\Ec#(
GaBTj_3
/* _]|Qec)
**SiteInfoBean.java <m-.aK{9
*/ y ~AmG~
package NetFox; D.*>;5:0'
l67KJ
>"("*3AO
public class SiteInfoBean { ?`AGF%zp
#$'FSy#
vM4<d>
private String sSiteURL; //Site's URL ]V<-J
private String sFilePath; //Saved File's Path 8_xLl2
private String sFileName; //Saved File's Name /P+q}L%
private int nSplitter; //Count of Splited Downloading File aB"xqh)a}T
6D/'`
C1QV[bJK
public SiteInfoBean() KcXpH]>!9
{//nSplitter的缺省值为5 v01#>,R
//default value of nSplitter is 5 :a3xvN-l
this("","","",5); S " pI
} GGnp Pp
w%xCTeK[
P5?<_x0v4b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;>ozEh#8w
{ x(~<tX~
sSiteURL= sURL; 8&E}n(XE
sFilePath = sPath; V'StvU
sFileName = sName; nPA@h
this.nSplitter = nSpiltter; Q~Ea8UT.#
#H5=a6E+q
g`?:=G:a*
} V3.t;.@
&mkpJF/
(E!!pz
public String getSSiteURL() =+oZtP-+o
{ 97LpY_sU
return sSiteURL; g}Qx`65:
} P!<[U!<hH
J(iV0LAZb
K ,isjh2
public void setSSiteURL(String value) BSzkW}3q9
{ CL3xg)x6
sSiteURL = value; &]iKriG
} )2.)3w1_4
g>0vm2|
'Q|c@t
public String getSFilePath() 2 ZG@!Y|
{ FpVV4D
return sFilePath; M{KW@7j
} 3,6Ox45
K=\&+at1
+AI`R`Tm
public void setSFilePath(String value) IZNOWX|Z;
{ O@&+} D>
sFilePath = value; REA;x-u*
} !OE*z $\
BD*G1k_q
/A07s[L
public String getSFileName() #`ejU&!6
{ J^zi2jtV
return sFileName; [Z<Z;=t
} g9>~HF$U
KIus/S5 RC
IeTdN_8
public void setSFileName(String value) Ly #_?\bn
{ GozPvR^/
sFileName = value; 7%d8D>uw8
} y4jU{,
<z0WLw0'z
Q5n`F5
public int getNSplitter() `;%ZN
{ =G${[V\
return nSplitter; >l5u54^3K
} x;#zs64f
q|dH~BK
~5OL6Bi-q
public void setNSplitter(int nCount) {IM! Wb
{ |b.z*G
nSplitter = nCount; QLo(i
} `f`TS#V
} jRj=Awy
Vxdp|
xeA#u J
/* j]5WK_~M
**Utility.java H^AE|U*-G
*/ HlB]38
package NetFox; <bUe/m
b"CAKl
NiSO'=y$n
public class Utility { +4)7j&L
|g&ymFc
9 [Y-M
public Utility() SW 8x]B
{ *l+Cl%e
Xu}U{x>
!m y8AWO'
} fZN><3MO>
[kB `
//线程睡眠 bbN%$/d
public static void sleep(int nSecond) }iiHr|l3
{ p,!$/Q+l
try{ .#w6%c@
Thread.sleep(nSecond); dE(tFZx
} (K{5fC
catch(Exception e) WZewPn>#q
{ q31>uF
e.printStackTrace (); \~DM
} _GA$6#]
} +RDJY(Y$
93Yn`Av;
//日志 {|<"C?
public static void log(String sMsg) T0QvnIaP
{ e@]-D FG
System.err.println(sMsg); mOBACTY^
} HZjf`eM,
v/QUjXBr
= [@)R!3H
public static void log(int sMsg) W<,F28jI3v
{ -1%OlKC
System.err.println(sMsg); "VUYh$=[
} L^J-("e_
} <iLM{@lZvJ
E4%j.
L8$1K&!
/* 2Aq~D@,9=:
**TestMethod.java a\5FAkI
*/ l* dV\ B
package NetFox; $95~5]-nh
})F*:9i*
z~oDWANP
public class TestMethod { 1Y/$,Oa5
&Z^(y}jPr
<=um1P3X
public TestMethod() E1V^}dn
{ ///xx/weblogic60b2_win.exe |(R5e
try{ F2I 5qC/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Snw3`|Y~<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qYB~VE03
SiteFileFetch fileFetch = new SiteFileFetch(bean); kBWrqZ6
fileFetch.start(); yt0,^*t_
} %5'6Tj
catch(Exception e){e.printStackTrace ();} S33j?+Vs
WrGK\Vw[
}d Ad$^
} .TB"eUy
D56<fg$
|L3X_Me
public static void main(String[] args) _S?qDG{E|
{ J m{
new TestMethod(); cNK)5- U
} s95F#>dr
} Y}G_Z#-!
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