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)); *d C|X
} P?V+<c{
for(int i=0;i<nEndPos.length-1;i++) =F_uK7W
{ @`KbzN_h/
nEndPos = nStartPos[i+1]; =hTJp/L
} #B~;j5
nEndPos[nEndPos.length-1] = nFileLength; 5%2~/ "
} 'S6zkwC]
} M _< |n
nR,QG8
Culv/
//启动子线程 >P j#?j*Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6<W^T9}v@/
for(int i=0;i<nStartPos.length;i++) esTL3 l{[
{ t#P7'9Se8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |.Vgk8oTl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v];YC6shx
nStartPos,nEndPos,i); 8i] S[$Fc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (Z>?\iNJ
fileSplitterFetch.start(); mh"PAp
} o=Z:0Ukl]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *Hn=)q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); zqj|$YNC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Fxa{ 9'99
nEndPos = " + nFileLength); ,|RKM
// fileSplitterFetch[nPos.length-1].start(); i}8OaX3x
(.N n|lY<i
12#yHsk
//等待子线程结束 @lDnD%vZ`
//int count = 0; n>u_>2Ikkj
//是否结束while循环 9<rs3 84
boolean breakWhile = false; ]vf_4QW=
OSO MFt
m&=Dy5
while(!bStop) Rp2h[_>
{ GjwH C{
write_nPos(); 8g8eY pG
Utility.sleep(500); %TI3Eb
breakWhile = true; jX4$PfOhR
^!^M Gzu
-sv%A7i
for(int i=0;i<nStartPos.length;i++) r jn:E
{ *^@b0f~vj
if(!fileSplitterFetch.bDownOver) [@qjy*5p
{ $A~aNI
breakWhile = false; ILDO/>n
break; &V axv$v}
} !j7mY9x+
} AB%i|t
if(breakWhile) " l|`LjP5M
break; VOj7Tz9UD
\1<aBgKi
cPZ\iGy
//count++; F6~ ;f;
//if(count>4) /D9#v1b
// siteStop(); _}47U7s8
} jl}9R]Y_2
J1(SL~e],
"\Dqtr w
System.err.println("文件下载结束！"); Y!]a*==
} }8 ;,2E*z
catch(Exception e){e.printStackTrace ();} H5d@TB,`
} 56YqYu.
91R7Rrne
vxf09v{-
//获得文件长度 ABoB=0.l
public long getFileSize() nt_Cb*K<
{ K+/wJ9^B
int nFileLength = -1; fCu;n%
try{ T0fm6 J
URL url = new URL(siteInfoBean.getSSiteURL()); Hj`'4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9?sY!gXc
httpConnection.setRequestProperty("User-Agent","NetFox"); dCn9]cj/
n\Lsm
T] H'l
int responseCode=httpConnection.getResponseCode(); V1Ft3Msq
if(responseCode>=400) hy#nK:B
{ MA9E??p3\
processErrorCode(responseCode); +(Hp ".gU
return -2; //-2 represent access is error s w>B
} $27OrXQ|
*lZ V3F
rgXX,+cO
String sHeader; q}jh>`d
V&j]*)
VXk[p
for(int i=1;;i++) lrkgsv6
{ LsGO~EiJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3`D*AFQc
//Utility.log(in.readLine()); `;G@qp:A
sHeader=httpConnection.getHeaderFieldKey(i); 1k"t[^
if(sHeader!=null) ;xh.95BP`
{ =_E$* }
if(sHeader.equals("Content-Length")) 8@;R2]Q
{ IV1O/lGp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '%e@7Cs
break; )Dv;,t
} 66B,Krz1n
} 4VF]tX?o
else (JOR: 1aT
break; Z! /_H($
} Yt_tAm
} 6&i])iH
catch(IOException e){e.printStackTrace ();} 7^.g\Kt?
catch(Exception e){e.printStackTrace ();} j?tE#
+#>nOn(B
6Yva4Lv
Utility.log(nFileLength); $5ea[nc
jN= !Q&^i[
{LKW%G7
return nFileLength; GRj [2I7:
} ]n1#8T&<*z
8:I-?z;S
StNA(+rT
//保存下载信息（文件指针位置） +Y+fM
private void write_nPos() 0%rE*h9+
{ wmbG$T%k
try{ (@BB@G
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~_CZ1
output.writeInt(nStartPos.length); HYdt3GtJ?
for(int i=0;i<nStartPos.length;i++) ZBK)rmhMx
{ ~.e~YI80
// output.writeLong(nPos); RK&RMN8@
output.writeLong(fileSplitterFetch.nStartPos); LCIe1P2
output.writeLong(fileSplitterFetch.nEndPos); USgO`l\}4
} p+nB@fN/
output.close(); ae0Mf0<#)
} R-iWbLD
catch(IOException e){e.printStackTrace ();} SdI>
catch(Exception e){e.printStackTrace ();} jv29,46K
} UY *Z`$
ze8MFz'm
'g<FL`iP
//读取保存的下载信息（文件指针位置） AKLFUk
private void read_nPos() o<s~455m/
{ M_$;"NS+}
try{ j~in%|^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [p0_I7
int nCount = input.readInt(); 6m(+X MS
nStartPos = new long[nCount]; |1!OwQax
nEndPos = new long[nCount]; iH)vLD
for(int i=0;i<nStartPos.length;i++) Lrt~Q:z2u
{ j}}as
nStartPos = input.readLong(); +4IaX1.
nEndPos = input.readLong(); P|fh4b4
} N-<,wUxf
input.close(); ?6\A$?
} @v6{U?
catch(IOException e){e.printStackTrace ();} ~2Mcw`<
catch(Exception e){e.printStackTrace ();} ?ODBW/{[G
} M@. 2b.
ygV-Fv>PQ
S[/D._5QD%
private void processErrorCode(int nErrorCode) L?(1 [jB4G
{ [--] ?Dr
System.err.println("Error Code : " + nErrorCode); ZD?LsD3
} zU|'IW&
TuwSJS7
ZQ\O| n8
//停止文件下载 Z2]\k|%<Fa
public void siteStop() ZOJ7^g
{ ,/p.!+
bStop = true; )q{e L$
for(int i=0;i<nStartPos.length;i++) v~!_DD au
fileSplitterFetch.splitterStop(); CfOhk
<HW2W"Go\
8f&#WIZ
} uF*tlaV6
} :G<~x8]k0
//负责部分文件的抓取 YMwL(m1
**FileSplitterFetch.java >o"0QD
*/ ?,Wm|xY
package NetFox; UPuG&A#VV
&:C(,`~
6se[>'5
import java.io.*; srU*1jD)
import java.net.*; :?3y)*J!
~05(92bK
8\`otJY
public class FileSplitterFetch extends Thread { *U,W4>(B
cbx( L8
1[?xf4EMG
String sURL; //File URL ARB^]
long nStartPos; //File Snippet Start Position <5c^DA
long nEndPos; //File Snippet End Position M1Th~W9l
int nThreadID; //Thread's ID p!LaR.8]
boolean bDownOver = false; //Downing is over u&Xn#fh
boolean bStop = false; //Stop identical ^12}#I
FileAccessI fileAccessI = null; //File Access interface +\B.3%\-
+227SPLd
!?{%9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException AT^MQvn
{ kqS_2[=]
this.sURL = sURL; TGG-rA6@Lx
this.nStartPos = nStart; ueJ_F#y
this.nEndPos = nEnd; n]_<6{: U
nThreadID = id; wcDb| H&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u,S}4p&l
} G:PcV_ihx
MOP#to)k&
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public void run() z 2Ao6*%
{ XV<{tqa
while(nStartPos < nEndPos && !bStop) } qr ,
{ YksJ$yH^
>56;M7b(K
5AAPtZ\lH
try{ [iG4qI
URL url = new URL(sURL); URxy*)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {F$MZ2E
httpConnection.setRequestProperty("User-Agent","NetFox"); Gc:oSvm
String sProperty = "bytes="+nStartPos+"-"; }zwHUf9q1
httpConnection.setRequestProperty("RANGE",sProperty); MB(l*ju0
Utility.log(sProperty); ! lm0zR
oIY@xuj
ca!x{,Cvnj
InputStream input = httpConnection.getInputStream(); naW!Mga
//logResponseHead(httpConnection); v0~*?m4
@{^6_n+gT%
rt!Uix&
byte[] b = new byte[1024]; .l]w4Hf
int nRead; G2_l}q~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k3B]u.Lo
{ PqwoZo0j
nStartPos += fileAccessI.write(b,0,nRead); xcu:'7'K[
//if(nThreadID == 1) IqmQQ_KH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,OaPrAt-
} \_zp4Xb2
{ BDUl3T
92Df.xI}
Utility.log("Thread " + nThreadID + " is over!"); Z<Ke/Xi
bDownOver = true; h*X u/aOg
//nPos = fileAccessI.write (b,0,nRead); gK"E4{y_@
} JNgl
catch(Exception e){e.printStackTrace ();} S"joXmJ/-C
} 7S]akcT/
} J*'#! xIa
"( P-VX
D4CiB"g3*
//打印回应的头信息 :k.C|V!W
public void logResponseHead(HttpURLConnection con) Nm=\~LP90
{ UZRCJ
for(int i=1;;i++) C{Er%
{ O'<cEv'B*
String header=con.getHeaderFieldKey(i); g_t1(g*s
if(header!=null) "G @(AE(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x3?:"D2
Utility.log(header+" : "+con.getHeaderField(header)); !8i[.EAT
else Ax;i;<md
break; -_|U"C$
} i\u m;\
} cv/
V9i[dF
VWR6/,N^_
public void splitterStop() (GJW3
{ T*sB Wn'am
bStop = true; )\r;|DN
} Z3]ut#`
")ZsY9-P
F~_)auH
} vT>ki0P_;
4{oS(Vl!
Yy:Q/zwo
/* %o9;jX
**FileAccess.java /SDDCZ`;|c
*//文件访问(定位，写) XT 'v7
package NetFox; wst)O{4
import java.io.*; ir*T,O 2J
H+ Y+8
6S2v3
public class FileAccessI implements Serializable{ v"dj%75O?e
;\Vi~2!8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /_MEb42&
RandomAccessFile oSavedFile; cfEi]
long nPos; 2m/=0sb\{
'v*Y7zZ#K
BVpRkUC"
public FileAccessI() throws IOException L=wg"$
{ hhVyz{u
this("",0); m;"i4!
} m!-,K8
)cX6o[oia
X3j<HQcK
public FileAccessI(String sName,long nPos) throws IOException j3`"9bY
{ !(EJ.|LH
oSavedFile = new RandomAccessFile(sName,"rw"); #YMU}4=:
this.nPos = nPos; N6BFs(
oSavedFile.seek(nPos); | Djgm7$*
} `II/nv0jn
^KK6 d
a:(.{z?nM
public synchronized int write(byte[] b,int nStart,int nLen) s1eGItx[w
{ g :me:M
int n = -1; 5-ju5z?=
try{ HFL(t]
oSavedFile.write(b,nStart,nLen); _g(4-\
n = nLen; ['SZe0
} mzl %h[9iI
catch(IOException e) pU|SUM
{ S>oQm
e.printStackTrace (); 6(`Bl$M9
} aBO%qmtt
MWS=$N)v*
5`B!1
return n; qdFYf/y
} mGmkeD'
XY;cz
Gn*vVZ@`x
} "c6(=FFq
OBY
Q( C\X
/* prC1<rm
**SiteInfoBean.java xCOC5f5*@
*/ :Sx!jx>W
package NetFox; )PU?`yLTr
#UcqKq
K0i[D"
public class SiteInfoBean { D4x~Vk%H
x*A_1_A
Ifm|_
private String sSiteURL; //Site's URL 8tM40/U$
private String sFilePath; //Saved File's Path 0!c^pOq6
private String sFileName; //Saved File's Name qe!\ oh
private int nSplitter; //Count of Splited Downloading File y/ #{pyJ
h] (BTb#-
qd9CKd
public SiteInfoBean() mE"?{~XVL
{//nSplitter的缺省值为5 (YbRYu
//default value of nSplitter is 5 d5zF9;[
this("","","",5); :h>d'+\
} \B'rWk33,
1%YjY"j+
(1r.AG`g
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Khbkv
{ ab1qcQ<
sSiteURL= sURL; EPQ~V
sFilePath = sPath; l;I)$=={=
sFileName = sName; d85\GEF9i
this.nSplitter = nSpiltter; ?t&sT
38wt=0br
`3Gjj&c
} %d5;JEgA:g
LeA=*+zP[
l@8UL</W
public String getSSiteURL() F j_r n
{ 'Jb6CRn
return sSiteURL; Nj2f?',;U
} o5(p&:1M
[/}y!;3iXM
%E95R8SL
public void setSSiteURL(String value) :GU6v4u
{ edh?I1/
sSiteURL = value; *RQkL'tRf
} "JLKO${ Y
.!ThqYo
{ jnQoxN
public String getSFilePath() *^XfEO
{ q$$:<*Uy
return sFilePath; e>-a\g
} fX,L;Se"
6B)3SC
7gR8Wr ^
public void setSFilePath(String value) =(f+geA"hm
{ 'E2\e!U/
sFilePath = value; e Ir|%
} W|K"0ab
}s_'q~R
1nv#Ehorg
public String getSFileName() S4j`=<T,
{ j +j2_\
return sFileName; <MhjvHg
} !c`KzqP
x/NR_~Rnk
qRg^Bp'VD#
public void setSFileName(String value) <_HK@E<_HO
{ gO*:<B g
sFileName = value; v$R+5_@[l
} FhZ^/= As
i<N[sO
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public int getNSplitter() D-7PO3F:F
{ *xEcX6ZHX
return nSplitter; 93="sS
} &UhI1mi]h
@J~n$^ke
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public void setNSplitter(int nCount) =&QC&CqEi
{ ~Qzb<^9]
nSplitter = nCount; W+[XNIg5
} |=C&JA
} O2|[g8(_F
tZS-e6*S
huTa Ei
/* ~n:dHK`
**Utility.java -@49Zh2'
*/ D-8NDa(`
package NetFox; 4\)"Ih
2s{PE
?*i qg[:
public class Utility { bT|NZ!V
jtdhdA
W+3ZuAP\n
public Utility() ,Vz 1l_7
{ MHN?ZHC)
74VN3m
'JR2@W`]]
} Mp=2}d%P
HZBU?{
//线程睡眠 l0Myem v?z
public static void sleep(int nSecond) Cx$M
{ <szD"p|K
try{ nJJ9>#<g$
Thread.sleep(nSecond); Nf0'>`/
} %vjLw`
catch(Exception e) )3_I-Ia
{ \%nFCK0
e.printStackTrace (); `8Y& KVhu
} +*2wGAT
} aa8xo5tIp
gxEa?QH
//日志 -!uut7Z|
public static void log(String sMsg) CmaV>
{ ]:CU.M1
System.err.println(sMsg); 8(R%?>8
} ueO&%
&61;v@
7Y$#* 7
public static void log(int sMsg) W2L:
{ D9H(kk
System.err.println(sMsg); TrxZS_
} j4wcxZYY~
} ,?Pn-aC+
d,}fp)
h^F^|WT$
/* M_tY:v
**TestMethod.java Ri]7=.QI`
*/ ~~[Sz#(
package NetFox; ;[%_sVIy
RZm}%6##ZC
'=!@s1;{[;
public class TestMethod { (0s7<&Iu
LG6VeYe|\X
V[-4cu,Ph^
public TestMethod() ^06f\7A
{ ///xx/weblogic60b2_win.exe w9I7pIIl
try{ IYm~pXg^0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %{\|/#>:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k0IW,z%
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1:<=zqh0
fileFetch.start(); 4`F(RweGx
} >$=-0?.
catch(Exception e){e.printStackTrace ();} ]3tg|?%B
;SAurG$
Jx;"@
} o:kiIZ]
~F8M_
S pxkB!
public static void main(String[] args) c$),/0td|
{ {6%vmMbJ
new TestMethod(); Fj\}&H*+
} YUo{e=m|
} 7a_pO1MBL
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