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)); $dKfUlO
} ww7nQ}H5(
for(int i=0;i<nEndPos.length-1;i++) KJOb1MM
{ #tHYCSr]
nEndPos = nStartPos[i+1]; &x\)] i2f
} 'D`lVUB
nEndPos[nEndPos.length-1] = nFileLength; qGV(p}$O
} &l]F&-
} QOUyD;0IW
!2HF|x$
M0lJyzJ
//启动子线程 r`<e<C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;}f {o^]'
for(int i=0;i<nStartPos.length;i++) 1+-Go}I
{ Kgi`@`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t^KQv~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iR9duP+
nStartPos,nEndPos,i); xg, 9~f[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ob/<;SrU<
fileSplitterFetch.start(); @.a59kP8X
} mD% qDKI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZDzG8E0Sq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]?T^tJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Hpz1Iy@
nEndPos = " + nFileLength); ZG1TRF "
// fileSplitterFetch[nPos.length-1].start(); 6l2O>V
QQN6\(;-
Wd!Z`,R
//等待子线程结束 +ug2p;<B
//int count = 0; k=kkF"
//是否结束while循环 =s*c(>
boolean breakWhile = false; )K]p^lO
J5jI/P
6p&2A
while(!bStop) (z)#}TC
{ @8m%*pBg
write_nPos(); =to.Oa RR
Utility.sleep(500); p|nPu*R-\
breakWhile = true; U_'M9g{,<
OhN2FkxL
Ws0)B8y,|
for(int i=0;i<nStartPos.length;i++) ,.2qh|Ol
{ DeW{#c6
if(!fileSplitterFetch.bDownOver) DVwB}W~
{ g.!k>_g`
breakWhile = false; PB"=\>]`N
break; P8h|2,c%
} JBHPI@Qt%
} XaE*$:
if(breakWhile) H)Me!^@[D
break; 'j{o!T0
)i.pE]!+
w{_g"X
//count++; qTbc?S46pt
//if(count>4) A:y^9+Da
// siteStop(); j~.tyxOq#
} 0S>L0qp
|BhL.
/CyFe<t
System.err.println("文件下载结束！"); f$5pp=s:n
} o/a2n<4
catch(Exception e){e.printStackTrace ();} R#y"SxD()
} Dpu?JF]
98 NFJ
vpT\CjXHZ
//获得文件长度 m*B4a9f
public long getFileSize() )f^^hEIS
{ #b)`as?!1
int nFileLength = -1; |N6.:K[`
try{ K% snE7X?)
URL url = new URL(siteInfoBean.getSSiteURL()); \Ezcr=0z{j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3rHn?
httpConnection.setRequestProperty("User-Agent","NetFox"); ' e!WZvr
M6A0D+08
BUsxgs"),
int responseCode=httpConnection.getResponseCode(); iyR"O1]
if(responseCode>=400) 9dAtQwGR"6
{ `S-%}eUv
processErrorCode(responseCode); {"$[MYi:
return -2; //-2 represent access is error CGK]i.N
} M,kO7g
$.w$x1
C,mfA%63
String sHeader; ojm IEzsz
3HcduJntl
noz1W ]
for(int i=1;;i++) Yd~J(
{ #ucb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); | X#!5u
//Utility.log(in.readLine()); 8b-mW>xsA
sHeader=httpConnection.getHeaderFieldKey(i); }:$ot18
if(sHeader!=null) NySa%7@CD
{ k$f2i,7'
if(sHeader.equals("Content-Length")) (dyY@={q
{ F(lJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d)Z&_v<|
break; o+XQMg
} +rSU
} OR $i,N|
else ue+{djz[4
break; q=`n3+N_H~
} #rr!ApJ
} 0J466H_d{
catch(IOException e){e.printStackTrace ();} nnT#S
catch(Exception e){e.printStackTrace ();} +%klS `_
,g0t&jITo
="vg/@.>i
Utility.log(nFileLength); $*%,
kI@<H<
j_<!y(W
return nFileLength; ~:f..|JM
} R"P-+T=7M
R*lq7n9
9oO~UP!ag
//保存下载信息（文件指针位置） C<(oaeQY
private void write_nPos() Fih pp<
{ Ow4(1eE_
try{ E JuTv%Y8
output = new DataOutputStream(new FileOutputStream(tmpFile)); <y^_&9
output.writeInt(nStartPos.length); @/^mFqr2
for(int i=0;i<nStartPos.length;i++) zN]%p>,)HB
{ jTt9;?)
// output.writeLong(nPos); 0!lWxS0#=
output.writeLong(fileSplitterFetch.nStartPos); a <?~1pWtc
output.writeLong(fileSplitterFetch.nEndPos); vFntzN>#
} a oU"
output.close(); W~D_+[P|_
} u|Mx}
catch(IOException e){e.printStackTrace ();} +D]raU
catch(Exception e){e.printStackTrace ();} 0D@$
} -/{FGbpR;
{b4`\I@<
1Pw1TO"Z
//读取保存的下载信息（文件指针位置） VlA]A,P}i
private void read_nPos() ;zD4#7=
{ }a~hd*-#
try{ ~).D\Q\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jLVD37 P^
int nCount = input.readInt(); t&{;6MiE
nStartPos = new long[nCount]; =VuSi(d;e{
nEndPos = new long[nCount]; &*+$38XE^
for(int i=0;i<nStartPos.length;i++) llX `
{ b=:ud[h
nStartPos = input.readLong(); 4FRi=d;mP
nEndPos = input.readLong(); &Q?@VNi
} TK\3mrEI
input.close(); ,7)hrA$(
} -W('^v_*
catch(IOException e){e.printStackTrace ();} w($a'&d`0
catch(Exception e){e.printStackTrace ();} Gg9MAK\C9
} T&]-p:mg^
lNg){3
6 V0Ayxg7
private void processErrorCode(int nErrorCode) |3,WiK='
{ IV. })8
System.err.println("Error Code : " + nErrorCode); #c@&mus
} \uPzj_kU6
7mMGH(
"*t6KXVaM
//停止文件下载 a,RCK~GR
public void siteStop() A<)n H=G&
{ 65~E<)UJ
bStop = true; 3[fm|aU
for(int i=0;i<nStartPos.length;i++) eP>_CrJb
fileSplitterFetch.splitterStop(); >;c);|'}q
o$.#A]Flb
={P`Tve
} 9!Mh(KtQ
} (=7"zECq#
//负责部分文件的抓取 g[pU5%|"[
**FileSplitterFetch.java f- 9t
*/ 2n@`Og_0
package NetFox; [//i "Nm
VrZfjpV
^*.$@M
import java.io.*; 23^>#b7st
import java.net.*; U; oXX
~bb6NP;'L
P5_Ajb(@'
public class FileSplitterFetch extends Thread { { %X2K
lF!PiL
vNs%e/~vj
String sURL; //File URL <<MpeMi
long nStartPos; //File Snippet Start Position gp`@dn';
long nEndPos; //File Snippet End Position ;(`bP
int nThreadID; //Thread's ID xE<H@@w
boolean bDownOver = false; //Downing is over ~-7/9$ay5
boolean bStop = false; //Stop identical Ex p?x
FileAccessI fileAccessI = null; //File Access interface {\1bWr8!U
hTn"/|_SW
jerU[3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y%"$v0D
{ bOr11?
this.sURL = sURL; a`w=0]1&*
this.nStartPos = nStart; >EJ{ *
this.nEndPos = nEnd; KUZi3\p9W>
nThreadID = id; wCLniCt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )Ac,F6w
} +S(# 7
3/n?g7B
?Xypn#OPt
public void run() Y`ip.Nx
{ Bzwll
while(nStartPos < nEndPos && !bStop) /C!~v!;e
{ kb2C9<
c%doNY9Q
^vd$j-kjTP
try{ LvG$J*
URL url = new URL(sURL); % E1r{`p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ly2,*\7
httpConnection.setRequestProperty("User-Agent","NetFox"); Y0,{fw<
String sProperty = "bytes="+nStartPos+"-"; PDD2ouv4
httpConnection.setRequestProperty("RANGE",sProperty); `S|F\mI~
Utility.log(sProperty); $GRwk>N
9abUh3
a[~[lk=7
InputStream input = httpConnection.getInputStream(); 3pWav 1"
//logResponseHead(httpConnection); L.@$rFhA
|9S8sfw
<h/q^|tZ{
byte[] b = new byte[1024]; M{24MF
int nRead; g.9C>>tj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _$>);qIP4
{ aF?_V!#cT
nStartPos += fileAccessI.write(b,0,nRead); vf3)T;X>
//if(nThreadID == 1) geyCS3 :p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G)<B7-72;
} )4uWB2ZRoi
A2ye ^<-C.
BGibBF^
Utility.log("Thread " + nThreadID + " is over!"); H I|a88
bDownOver = true; a8T9=KY^
//nPos = fileAccessI.write (b,0,nRead); cOP'ql{"
} e#HPU
catch(Exception e){e.printStackTrace ();} =A6*;T"W
} kQ\ $0=6N9
} q$"u<
S&UP;oc
_oc6=Z
//打印回应的头信息 q&@s/k
public void logResponseHead(HttpURLConnection con) SzpUCr"
{ &{8:XJe*,%
for(int i=1;;i++) V"4L=[le
{ }V]b4t
String header=con.getHeaderFieldKey(i); rwj+N%N
if(header!=null) >WLX5i&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NHyUHFY
Utility.log(header+" : "+con.getHeaderField(header)); q#AEu xI1
else M(+Pd_c6
break; 8+w*,Ry`
} Wd;t(5Xl
} h623)C;
MS""-zn<
apm%\dN
public void splitterStop() m^L!_~
{ %l&oRBC
bStop = true; }TMO>eB'
} *.nSv@F
aWTurnee^
ZJs~,Q
} D1y`J&A>Q
'M6+(`x
bI0xI[#Q
/* }F{s\qUt
**FileAccess.java Ox J0."
*//文件访问(定位，写) lGYW[0dy
package NetFox; ^)]U5+g?
import java.io.*; )=GPhC/sw
hev;M)t
7 w,D2T
public class FileAccessI implements Serializable{ hGD@v{/
*bp09XG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )e0kr46
RandomAccessFile oSavedFile; P@UE.0NYX
long nPos; ~ `}),aA
n32"cFPpT
nQV0I"f]?]
public FileAccessI() throws IOException $#f_p-N
{ ':_9o5I
this("",0); ktfm
} .:&`PaMt
ep"{{S5g
BJ5MCb.w
public FileAccessI(String sName,long nPos) throws IOException '/qy_7O
{ d%k7n+ICQ4
oSavedFile = new RandomAccessFile(sName,"rw"); ~-vCY
this.nPos = nPos; AmIW$(Ce
oSavedFile.seek(nPos); E'4Psx9: =
} 4#>Z.sf
sTP\}
8?LT*>!
public synchronized int write(byte[] b,int nStart,int nLen) ( y!o
{ HUjX[w8
int n = -1; kF^4kCJ@
try{ 4Lg ,J9
oSavedFile.write(b,nStart,nLen); sDNWB_~
n = nLen; _Vp"G)1Y
} *y?6m,38V
catch(IOException e) 0^S$_L
{ DcBAncsK
e.printStackTrace (); ~.3v\Q
} RN 4?]8
?l%4 P5
4F.,Y3
return n; N,lr~6)
} C[%Qg=<
55s5(]`d
.g}N@
} BNJ0D
Z:^#9D{
M>5OC)E
/* + Fo^NT
**SiteInfoBean.java BAXu\a-C_
*/ !`N:.+DT
package NetFox; pnSKIn
ZMlBd}H
OR6vA5J
public class SiteInfoBean { Lqxhy s
vrb@::sy0T
v\|jkzR5Y
private String sSiteURL; //Site's URL `w#VYs|k
private String sFilePath; //Saved File's Path 2iM}YCV
private String sFileName; //Saved File's Name v\dQjQu8m
private int nSplitter; //Count of Splited Downloading File Tk[]l7R~
(bv{17K
#z>I =gl
public SiteInfoBean() O^CBa$
{//nSplitter的缺省值为5 uQc("F
//default value of nSplitter is 5 F-zIzzb&O
this("","","",5); \E,2VM@6
} (N&i4O-I
py7Zh%k
D"aK;_W@h
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rfVQX<95=/
{ ,gZp/yJ;
sSiteURL= sURL; 'gor*-o:wu
sFilePath = sPath; Kd 1=mC
sFileName = sName; ]/Nt
this.nSplitter = nSpiltter; 7xO05)bz
pLe4dz WA
^_3Ey
} x[};x;[ZE
Qq.$!$
#tA9`!
public String getSSiteURL() 5ZkR3/h e
{ >}F$6KM
return sSiteURL; sXEIC#rq
} OEl;R7aOB&
?xUl_
)t+pwh!8
public void setSSiteURL(String value) kOo Vqu
{ =(hBgNH
sSiteURL = value; mD7NQ2:wA
} `AE6s.p?
\^,Jh|T
>;Oa|G
public String getSFilePath() C)FO:lLr\
{ @C@9Tw2Y
return sFilePath; QyL]-zNg
} oy jkk
vkJyD/;=
`:7r5}(^
public void setSFilePath(String value) W=A0+t%XC
{ Tv7W)?3h
sFilePath = value; K_Y{50#
} XdDQ$'*X
@1'OuX^
Z?xaXFm_
public String getSFileName() \?v&JmEU
{ ~SBW`=aP}
return sFileName; 9;XbyA]
} MVzj7~+
p_BG#dRM
^PFiO 12
public void setSFileName(String value) V C VqUCc
{ R5QW4i9
sFileName = value; 2|\mBP`ok
} I`XOvSO
-"ZNkC=
V^FM-bg%9
public int getNSplitter() )G/=3;!
{ ESoqmCJjb:
return nSplitter; i#YDdz
} <H]PP6_g:
fhZwYx&t
::02?
public void setNSplitter(int nCount) ;p*L(8<YI
{ 9$v\D3<Z
nSplitter = nCount; *-]k([wV
} i| cA)
} |%8t.Z
vh"';L_*37
#]+BIr`
/* 4d@0v n{
**Utility.java M6MxY\uM
*/ mQ}\ptdfV
package NetFox; Eyf17
b?0WA.[{
J6EzD\.Y)
public class Utility { hU(
NM9ViYm>P
Rq|5%;1
public Utility() RgFpc*.T
{ "fNv(> -7s
jS3@Z?x?*
o/ \o-kC}
} 6flO;d/v
BYB9M
//线程睡眠 o(v`
public static void sleep(int nSecond) Z{(Gib~{N
{ !^L}LtqHI
try{ as3uz
Thread.sleep(nSecond); 9VaSCB
} |af<2(d
catch(Exception e) zB y%$5~Fw
{ 6k,@+@]t.
e.printStackTrace (); 0|va}m`<3G
} nq7)0F%e
} >/.jB/q
/:A239=+?
//日志 Yy[=E\z
public static void log(String sMsg) HWoMzp5="3
{ yT3K 2A
System.err.println(sMsg); i)@vHh82
} $aXYtHI
~:!&}e5
K'e!BZm6Q
public static void log(int sMsg) "[A&S!
{ [uie]*^
System.err.println(sMsg); j }^?Snq
} _mdJIa0D6k
} jkuNafp}
J=^5GfM)J
ND9;%<80
/* *sfz+8Y
**TestMethod.java !5m~qet.
*/ h*P0;V`UX
package NetFox; +f]I7e:qp
?\Y7]_]/
+W>tdxOh
public class TestMethod { V/OW=WCzN
F r2 +p
u_WW uo
public TestMethod() ~|KMxY(:
{ ///xx/weblogic60b2_win.exe ?aG~E
try{ d9D*w/clMi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =8r,-3lC;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OZObx
SiteFileFetch fileFetch = new SiteFileFetch(bean); < R@&<E6
fileFetch.start(); 2(D&jL
} |@-y+vbA*
catch(Exception e){e.printStackTrace ();} Dhg/>@tw
jS/$o?
nzYFa J+
} jaux:fU
dnPr2oI?I
~}~ yR*K%
public static void main(String[] args) GEb)nHQq
{ |("5 :m
new TestMethod(); hW cM.
} NX+ eig</-
} ;rF:$37^
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