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)); z1+rz%
} 1#qCD["8
for(int i=0;i<nEndPos.length-1;i++) LM'` U-/e$
{ +29;T0>a
nEndPos = nStartPos[i+1]; fC3IxlG
} s/[i>`g/9
nEndPos[nEndPos.length-1] = nFileLength; ud:?~?j&w
} U30)r+&
} V8Q#%#)FHe
5?kA)!|UB
8{+~3@T
//启动子线程 @sKAsn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pOI+
for(int i=0;i<nStartPos.length;i++) `Ik}Xw
{ 73~Mq7~8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }WGi9\9T&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), UKK}$B
nStartPos,nEndPos,i); M{kPEl&Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6sy%KO*A
fileSplitterFetch.start(); o33{tUp'
} +lha^){
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l3MbCBX2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k7{fkl9|#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s*CKFEb#
nEndPos = " + nFileLength); 0HD1Ob^@
// fileSplitterFetch[nPos.length-1].start(); 5,AQ~_,'\
,f?#i%EF&
0acY@_
//等待子线程结束 N2&aU?`e
//int count = 0; Y0B*.H Ae
//是否结束while循环 C6"!'6 W
boolean breakWhile = false; -N\{QX1Yd
nv$
)Elr8XLw
while(!bStop) L7Oytdc<
{ /#G"'U/
write_nPos(); {t/!a0\HS
Utility.sleep(500); ^/n[5@6H
breakWhile = true; S,(@Q~
PYHm6'5BtB
$PS5xD~@
for(int i=0;i<nStartPos.length;i++) b"FsT
{ ,t+ATaOF
if(!fileSplitterFetch.bDownOver) r3j8[&B"
{ Zc4hjg
breakWhile = false; Ic=V:
break; H+5]3>O-$
} ^LU[{HZV
} k13/yiv
if(breakWhile) +~fu-%,k
break; ?ha}&##
: m5u=:t
aq5<Ks`r
//count++; E7eVg*Cvi
//if(count>4) ygfqP
// siteStop(); ;5|EpoM
} &yA<R::o
(x^|
oNU* q.Q
System.err.println("文件下载结束！"); ONGe/CEXT
} mW-@-5Wda
catch(Exception e){e.printStackTrace ();} Zj7XmkL
} ;%Da {
@E>^\!nH
&\X;t|
//获得文件长度 {H+?DMh
public long getFileSize() BkZ%0rw%
{ CXQ?P
int nFileLength = -1; 8S02 3
try{ AX,Db%`l,
URL url = new URL(siteInfoBean.getSSiteURL()); tJu<#hX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sMS`-,37u
httpConnection.setRequestProperty("User-Agent","NetFox"); "G,*Z0V5
|wb7`6g
JZXc1R| 9
int responseCode=httpConnection.getResponseCode(); Ksp;bfe
if(responseCode>=400) " }ZD)7K
{ .E}});l
processErrorCode(responseCode); aXJe"IT.u
return -2; //-2 represent access is error ~Op1NE
} rka:.#!
UA8!?r-cR
3 #wj-
String sHeader; ;p_X7N
!xc7~D@om(
0/gcSW b
for(int i=1;;i++) ;Pa(nUE@
{ Kmnr}Lp9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K?tk&0
//Utility.log(in.readLine()); /< :;^B
sHeader=httpConnection.getHeaderFieldKey(i); $KKaA{0-
if(sHeader!=null) W^N"y&
{ +i>q;=~
if(sHeader.equals("Content-Length")) *@& "MZ/M
{ 1wgu%$|d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Yq^y"rw
break; LXfiSM{o
} Ww(_EW
} %pp+V1FH
else ~?&ijhZ
break; +n,BD C;
} w?tKL0c
} jwq"B$ap
catch(IOException e){e.printStackTrace ();} HxMsH5;
catch(Exception e){e.printStackTrace ();} .;:xx~G_Q
:}JZKj!}M
=e;wEf%`
Utility.log(nFileLength); fEjW7 c
LNZ#%R~r
?},ItJ#>)q
return nFileLength; uJOW%|ZN`
} VL{#.;QQa
^8m+*t
m#nxw
//保存下载信息（文件指针位置） 2 QmUg
private void write_nPos() }SV3PdE
{ v/czW\z
try{ [KH?5C
output = new DataOutputStream(new FileOutputStream(tmpFile)); DOerSh_0W
output.writeInt(nStartPos.length); zFtGc
for(int i=0;i<nStartPos.length;i++) OVyy}1Hx
{ u,m-6@il
// output.writeLong(nPos); 1955(:I
output.writeLong(fileSplitterFetch.nStartPos); 1,j9(m2
output.writeLong(fileSplitterFetch.nEndPos); QP B"EW
} ^PQV3\N
output.close(); <yS"c5D6
} +*J4q5;E[?
catch(IOException e){e.printStackTrace ();} 0'hxw3#
catch(Exception e){e.printStackTrace ();} OkZ!ZS h
} psC7IE<v
I{zE73
yU|ji?)e
//读取保存的下载信息（文件指针位置） ?X'* p<`
private void read_nPos() ?i~/gjp
{ }BJ1#<
try{ 5Mr;6 ]I<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {_Qxe1^g
int nCount = input.readInt(); / D ]B
nStartPos = new long[nCount]; 2]9<%-=S
nEndPos = new long[nCount]; U_- K6:tr
for(int i=0;i<nStartPos.length;i++) kkBU<L2
{ 2NknC>9(\
nStartPos = input.readLong(); @'*#]YU8
nEndPos = input.readLong(); CLfb`rF
} !)3s <{k#
input.close(); cf'}*$[S
} 8uxFXQ
catch(IOException e){e.printStackTrace ();} 5{q/z^]
catch(Exception e){e.printStackTrace ();} WdqK/s<jM
} j#,M@CE
LH#LBjOZk
l :Nxl
private void processErrorCode(int nErrorCode) z8|9WZ:
{ O{#Cddt:r
System.err.println("Error Code : " + nErrorCode); #U52\3G
} X-$td~r
eH955[fVd4
Sqf.#}u<=
//停止文件下载 KN:dm!A
public void siteStop() :EwA$`/
{ F[=lA"F^
bStop = true; yl<$yd0Zdu
for(int i=0;i<nStartPos.length;i++) }AW)R&m
fileSplitterFetch.splitterStop(); 3c^=<i %
j{R|]SjW2H
|/^aLj^u
} %`T5a<
} M3@fc,Ch
//负责部分文件的抓取 8.Ef5-m
**FileSplitterFetch.java ?gwbg*
*/ 6r=)V$K<
package NetFox; %]0U60
#}7m'F
b*F~%K^i$
import java.io.*; ~|{)h^]@
import java.net.*; sLa)~To
*rz(}(r
L*01l"5
public class FileSplitterFetch extends Thread { l;}7A,u
,beR:60)
,DuZMGg
String sURL; //File URL s<_LcQbt{
long nStartPos; //File Snippet Start Position ,XG|oo-
long nEndPos; //File Snippet End Position M(zY[O
int nThreadID; //Thread's ID qb>r\bc
boolean bDownOver = false; //Downing is over DgT.Lku?
boolean bStop = false; //Stop identical $;i$k2n:
FileAccessI fileAccessI = null; //File Access interface 60%~+oHi~
T:%wX9W
PnIvk]"Ab
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException FP9<E93br
{ g~hk-nXL.
this.sURL = sURL; 8+|V!q
this.nStartPos = nStart; q\t>D _lU
this.nEndPos = nEnd; *DCNu{6
nThreadID = id; FR,#s^kF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sx<+ *Trl
} <<On*#80w
0S:!Gv+
|z|)r"*\4
public void run() \v3>Eo[
{ ~q?"w:@;x
while(nStartPos < nEndPos && !bStop) _Kl{50}]
{ Na 9l#
$ lsRg:J
.V 3X#t
try{ zHoO?tGf
URL url = new URL(sURL); {iIg 4PzrU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #D LT-G0
httpConnection.setRequestProperty("User-Agent","NetFox"); h[je_^5
String sProperty = "bytes="+nStartPos+"-"; B,vHn2W
httpConnection.setRequestProperty("RANGE",sProperty); yp2'KES>
Utility.log(sProperty); TQ\wHJ
y)^CDe2xU
/>^`*e_
InputStream input = httpConnection.getInputStream(); m wEVEx24
//logResponseHead(httpConnection); N<Z)b!o%u
1Q&WoJLfR
9Ajgfy>
byte[] b = new byte[1024]; $Y 4ch ko
int nRead; FQ|LA[~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) n?e@):
{ o eJC
nStartPos += fileAccessI.write(b,0,nRead); %<J(lC9,C
//if(nThreadID == 1) Kjn&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \B>[je-d
} ? W2I1HEy
FM"GK '
AY/-j$5+?
Utility.log("Thread " + nThreadID + " is over!"); Fe&n,
bDownOver = true; 9u7n/o&8v6
//nPos = fileAccessI.write (b,0,nRead); 8A8xY446)
} V:G}=~+=
catch(Exception e){e.printStackTrace ();} JM+sHHs
} xH`j7qK.
} $~G0#JL
kf^-m/
|Y8Mk2,s
//打印回应的头信息 1YIux,2\
public void logResponseHead(HttpURLConnection con) LF9aw4:>Ou
{ g3|Y$/J7P
for(int i=1;;i++) ^E<~zO=Z
{ )0n29
String header=con.getHeaderFieldKey(i); #}t1
if(header!=null) # McK46B z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (ju aDn)
Utility.log(header+" : "+con.getHeaderField(header)); q]iKz%|Z/
else 9-a2L JI
break; im4e!gRE
} ^Z-.[Y
} $ gr6
0XR;5kd%
Wp7@
public void splitterStop() P$(WdVG
{ D,GPn%Wqi
bStop = true; <r7qq$
} e"o6C\c
L.TgJv43
?HEtrX,q
} p;n3`aVh
XC7Ty'#"KX
l?@MUsg+
/* +9 16ZPk
**FileAccess.java qUEd E`B
*//文件访问(定位，写) iJdrY6qd
package NetFox; JI+KS
import java.io.*; ^:cb $9F
B{OW}D$P#
_>jrlIfc
public class FileAccessI implements Serializable{ ;9p#xW6
=q"w2b&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [$1: &!(!
RandomAccessFile oSavedFile; U!a!|s>
long nPos; [U%ym{be^
je- ,S>U
@Hspg^
public FileAccessI() throws IOException HIPcZ!p
{ IFC%%It5,
this("",0); 0.J1!RIK/
} {FV,j.D
dJ%wVY0z=
^Hz
public FileAccessI(String sName,long nPos) throws IOException h\D_
{ &prdlh=UE
oSavedFile = new RandomAccessFile(sName,"rw"); V5e\%
this.nPos = nPos; teq^xTUF[
oSavedFile.seek(nPos); cotxo?)Zv
} =2.tu*!C
PmPyb>HK=P
b!4N)t>gl
public synchronized int write(byte[] b,int nStart,int nLen) 2d5}`>
{ #sz]PZ\
int n = -1; 2A*X Hvwb
try{ )Y&MIJ7>@
oSavedFile.write(b,nStart,nLen); ]^yV`Z8
n = nLen; #Dj"W8'zh
} ?Kx6Sf<i
catch(IOException e) 95.qAFB1
{ cW81
e.printStackTrace (); R/ALR
} z9k*1:
b"ol\&1 #
r,`Z.A
return n; y'J:?!S,Yu
} X[GIOPDx
VZT6;1TD$8
1&X}1
} u#a%(
A0cM(w{7_
38V $<w
/* ^3Z7dIUww
**SiteInfoBean.java $ 7UDz
*/ UC8vR>e\
package NetFox; Whv]88w{
HpB!a,R6B
7>nhIp))
public class SiteInfoBean { +8LM~voB
,~?A,9?%:
ttK,((=@
private String sSiteURL; //Site's URL M(n<Iu4^_
private String sFilePath; //Saved File's Path fnVW/23
private String sFileName; //Saved File's Name $l#v/(uFa
private int nSplitter; //Count of Splited Downloading File ( GFgt_
+G*"jI8W
azao`z
public SiteInfoBean() d u.HSXK
{//nSplitter的缺省值为5 Zw;$(="
//default value of nSplitter is 5 O{lIs_1.Z
this("","","",5); 8yHq7=
} qiG]nCq
mV6#!_"
a(PjcQ4dY
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ePV-yy
{ G*kE~s9R
sSiteURL= sURL; bWGyLo,
sFilePath = sPath; 6@"Vqm|HD
sFileName = sName; lTa1pp Zw
this.nSplitter = nSpiltter; Zij"/gx\
*0=fT}&!
Nc G,0K
} KotPV
+90u!r^v
@PYW|*VS
public String getSSiteURL() E)KB@f<g*
{ f:_=5e +
return sSiteURL; #^5a\XJb
} DY)D(f/&3
n?y'c^
^c/mj9M#C
public void setSSiteURL(String value) B1|?RfCe
{ Wr]O
sSiteURL = value; l_^T&xq8
} L@7Qs6G2u
oHxGbvQc
v*&Uk'4E
public String getSFilePath() T&?w"T2y
{ $-m@KB
return sFilePath; w@87]/4Rq
} _aVJ$N.
/)sDnJ1r
* eA{[
public void setSFilePath(String value) Gh2#-~|cB
{ zx ct(
sFilePath = value; ~RcNZ\2y
} VT'0DQ!NIq
o^6jyb!j
MzG5u<D
public String getSFileName() 1v;'d1Hg;
{ $8jaapNm@
return sFileName; d/l,C4p
} :lgHL3yl
2K3MAd{
J cP~-cp
public void setSFileName(String value) 7rH'1U
{ 0Xp nbB~~I
sFileName = value; %_>Tcm=
} 1#/6r :
g+e:@@ug
[6O04"6K
public int getNSplitter() @XeEpDn]
{ DNmb[
return nSplitter; $"/UK3|d
} DLU[<!C
VK9Q?nu
5(423"(y
public void setNSplitter(int nCount) Ud$Q0m&
{ ])eOa%
nSplitter = nCount; U9x4j_.q
} D`en%Lf!m
} |pBMrN+is
5f8"j$Az
+Dd"41
/* xtOx|FkYcl
**Utility.java n;%y
*/ 6*sw,sU[y
package NetFox; 3QIdN
P= e4lF.
'c#IMlv
public class Utility { ,E%1Uq"
9e]'OKL+
o\&~CW~@~
public Utility() expxp#S
{ q1STRYb
aQga3;S!
%?Rs*-F.~1
} 4e}{$s$Xx
*vb^N0P
//线程睡眠 n|6?J_{<b>
public static void sleep(int nSecond) 'm[6v}
{ f?Z|>3.2
try{ %Mh Q
Thread.sleep(nSecond); <3lUV7!
} '6O|H
catch(Exception e) {>/)5AGs
{ &2Q*1YXj
e.printStackTrace (); b"Zq0M0l
} s_xV-C#q@
} #Gd7M3
B=r0?%DX"1
//日志 TiQ^}5~M
public static void log(String sMsg) GYd]5`ri
{ EA6t36|TX
System.err.println(sMsg); +GYS26
} W+.{4K
inZi3@h)T
jM]d'E?ZLA
public static void log(int sMsg) ALfiR(!
{ 3^XVQS***
System.err.println(sMsg); t=Jm|wJnUA
} 3|zgDA
} ,7<DGI_y
5Q|sta!
c8<xFvYG
/* *!Y-!
**TestMethod.java b_|u<
*/ {M[~E|@D
package NetFox; ^Z#@3=
:&9TW]*g
Ge^Qar
public class TestMethod { 1+a@k
&Xv1[nByU
]rnXNn;
public TestMethod() I(n }<)eF
{ ///xx/weblogic60b2_win.exe p-,Iio+
try{ 0aogBg_@K
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ck$M(^)l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )km7tA 0a
SiteFileFetch fileFetch = new SiteFileFetch(bean); (8G$(MK
fileFetch.start(); h8jB=e, H
} 'y.JcS!|
catch(Exception e){e.printStackTrace ();} ab@=cL~^
{OCJ(^8i
qU-!7=}7
} 3b@VY'P
:Jk33 N4y0
7TpRCq#
public static void main(String[] args) (N0sE"_~I5
{ O#:&*Mv
new TestMethod(); bK4&=#Zh
} &{ZSE^
} 4jGLAor|
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