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)); }&ew}'*9)
} 5*"WS $
for(int i=0;i<nEndPos.length-1;i++) ) \cnz
{ R8% u9o
nEndPos = nStartPos[i+1]; y(Pv1=e
} Sr6iQxE
nEndPos[nEndPos.length-1] = nFileLength; \>/AF<2"
} _}`y3"CD7
} ~8Ef`zL
@$ )C pg
wGz_IL.D
//启动子线程 w@N)Pu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F0'o!A#|(
for(int i=0;i<nStartPos.length;i++) '~6l 6wi
{ SZgan
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^3&-!<*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0"@p|nAa
nStartPos,nEndPos,i); .}tpEvAw}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G)5Uiu:^X
fileSplitterFetch.start(); /X\:3P
} e+MsFXnB8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .fzns20u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +zFEx%3^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", toox`|
nEndPos = " + nFileLength); Im`R2_(]
// fileSplitterFetch[nPos.length-1].start(); ~r]$(V n
%+$!ctn
(n{!~'3
//等待子线程结束 /P{'nI
//int count = 0; ^6,}*@
//是否结束while循环 mc6W"
boolean breakWhile = false; s[*I210
F.R0c@&W
aOW~! f/M
while(!bStop) PPtJ/ }\
{ du=[r
write_nPos(); m`3gNox
Utility.sleep(500); VS<w:{*
breakWhile = true; QRY7ck:N
&4F iYZ
;xE1#ZT
for(int i=0;i<nStartPos.length;i++) +m6acu)N.
{ zL:k(7E
if(!fileSplitterFetch.bDownOver) Ef6LBNWY.
{ 8g 2'[ci$q
breakWhile = false; E+aE5wmr
break; #mv~1tL
} 4vPKDd
} ~\+mo
if(breakWhile) 'P >h2^z
break; O%s?64^U
rOq>jvy
$-]PD`wmY
//count++; MW.,}f
//if(count>4) !L'O")!3
// siteStop(); U| 1&=8l
} {B\lk:"X
oth=#hfU^
K}Pi"Le@W
System.err.println("文件下载结束！"); 6~(iLtd#
} ^F$iD (f
catch(Exception e){e.printStackTrace ();} kv3V|
} &uv7`VT
|Q~5TL>b
6?jSe<4x
//获得文件长度 "C%* 'k
public long getFileSize() ^cYt4NHXn
{ PxZMH=
int nFileLength = -1; Q-S5("
try{ /T/7O
URL url = new URL(siteInfoBean.getSSiteURL()); t.m C q4{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); so\8.(7n
httpConnection.setRequestProperty("User-Agent","NetFox"); xHdv?69,
N%+C5e<
[kg*BaG:
int responseCode=httpConnection.getResponseCode(); [U?a %$G>
if(responseCode>=400) 0\^K\J,.
{ ?9AtFT
processErrorCode(responseCode); 9ioV R
return -2; //-2 represent access is error ?t];GNU`l
} +QVe -
fxk6q$'
J"RmV@|
String sHeader; +aIy':P
C")NNs=
wrt^0n'r)c
for(int i=1;;i++) erZ%C <
{ I!-5 #bxD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); BnLE+X
//Utility.log(in.readLine()); ;F'/[l{+
sHeader=httpConnection.getHeaderFieldKey(i); ;*EPAC+
if(sHeader!=null) lvZ:Aw r
{ t12 xPtN1
if(sHeader.equals("Content-Length")) o.H(&ex|
{ Gj([S17\0:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CpF&Vy K
break; S~LTLv:>
} |G]M"3^
} s;-%Dfn
else at `\7YfQp
break; /WKp\r(Hp
} rn8t<=ptH3
} #>\+6W17U
catch(IOException e){e.printStackTrace ();} v5o@ls
catch(Exception e){e.printStackTrace ();} VjVL/SO/
' fm}&0
<oWoJP`G
Utility.log(nFileLength); x?B8b-*
?rgk
^aG=vXK`b
return nFileLength; uEKa FRm
} Tb6c]?'U
L>EC^2\
j8ebVq
//保存下载信息（文件指针位置） u?n{r
private void write_nPos() [3QKBV1\
{ w_!]_6%{b
try{ Hh1OD?N)
output = new DataOutputStream(new FileOutputStream(tmpFile)); [m3k_;[
output.writeInt(nStartPos.length); p#95Q
for(int i=0;i<nStartPos.length;i++) PH}^RR{H[
{ f}>S"fFI
// output.writeLong(nPos); hd}"%9p
output.writeLong(fileSplitterFetch.nStartPos); OjiQBsgnj
output.writeLong(fileSplitterFetch.nEndPos); \!4sd2Yi
} %v(\;&@
output.close(); (7g1eEK%
} c);(+b
catch(IOException e){e.printStackTrace ();} aBLE:v
catch(Exception e){e.printStackTrace ();} qrmJJSJ
} b 64~Y|8
l1qWl
=,=tSp
//读取保存的下载信息（文件指针位置） y$e'-v
private void read_nPos() G6b\4}E
{ 3%W R
try{ L>mv\D;o.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pPdOwK#
int nCount = input.readInt(); 9H<6k*
nStartPos = new long[nCount]; LAwl9YnG:
nEndPos = new long[nCount]; "3i=kvdz
for(int i=0;i<nStartPos.length;i++) S?5z
{ g2<xr;<t^
nStartPos = input.readLong(); v&EHp{8Qd
nEndPos = input.readLong(); 3Yd)Fm
} H+>l][
input.close(); ZdD]l*.\i
} Rz!E=1Y$
catch(IOException e){e.printStackTrace ();} F*_mHYa;
catch(Exception e){e.printStackTrace ();} H[{ch t h
} <eq93
IRZ?'Im
;?9u#FRtw
private void processErrorCode(int nErrorCode) |'2E'?\/x
{ P2`!)teN
System.err.println("Error Code : " + nErrorCode); ~ 0x9`~
} b:S#Sz$
nO~TW
TY=BP!s
//停止文件下载 eFPDW;
public void siteStop() 4V7{5:oa
{ ,zLi{a6
bStop = true; /EOtK|E
for(int i=0;i<nStartPos.length;i++) {qm(Z+wcmb
fileSplitterFetch.splitterStop(); b7/1]
Y24:D7Q
:LL>C)(f
} vTD`Ja#h
} yS#LT3>l
//负责部分文件的抓取 )h~MIpWR
**FileSplitterFetch.java SZCFdb
*/ L`ZH.fN
package NetFox; wL2d.$?TEg
CW Y'q
tF)aNtX4^
import java.io.*; }Jgz#d
import java.net.*; ]y,6
iaq0\d.[7
cvbv\G'aT
public class FileSplitterFetch extends Thread { $b#"Rv
h!f7/)|[o
j+n1k^jC
String sURL; //File URL ~<pGiW'w5
long nStartPos; //File Snippet Start Position EY(@R2~#J
long nEndPos; //File Snippet End Position oUm"qt_
int nThreadID; //Thread's ID WZ'3
boolean bDownOver = false; //Downing is over m&OzT~?_>N
boolean bStop = false; //Stop identical IN!m
FileAccessI fileAccessI = null; //File Access interface M[0@3"}}
EM*YN=So
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GCx]VN3&
{ ()vxTTa
this.sURL = sURL; v!ULErs
this.nStartPos = nStart; v.+-)RLQg
this.nEndPos = nEnd; 74%,v|
nThreadID = id; ~_SV`io
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z8Fbx+~"
} LD WFc_
Da)[mxJ
itM6S$
public void run() [t /hjm"$
{ _tN"<9v.
while(nStartPos < nEndPos && !bStop) :JSOj@s
{ m5sgcxt/
16o3ER
z@cL<.0CE
try{ &gkloP@
URL url = new URL(sURL); QhK]>d.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gu&?Gn oc
httpConnection.setRequestProperty("User-Agent","NetFox"); gydPy*
String sProperty = "bytes="+nStartPos+"-"; ^zQ;8)ng
httpConnection.setRequestProperty("RANGE",sProperty); U]fE(mpI9
Utility.log(sProperty); u(SdjLf:
)[6H!y5
z48,{H6h
InputStream input = httpConnection.getInputStream(); v\t$. _at
//logResponseHead(httpConnection); LI?rz<H!D
o\8yYX
L^)&"6oSa
byte[] b = new byte[1024]; _ 9Tv*@
int nRead; =_8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AMvM H
{ 8|?$KLz?F>
nStartPos += fileAccessI.write(b,0,nRead); G7`7e@{
//if(nThreadID == 1) \<~[uv'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q5iuK#/
} `w]=xe
&M~*w~w`
8(D>ws$
Utility.log("Thread " + nThreadID + " is over!"); w@4q D
bDownOver = true; yjpV71!M
//nPos = fileAccessI.write (b,0,nRead); ?K{CjwE.M
} ycRy!0l
catch(Exception e){e.printStackTrace ();} dV8mI,h
} qr(SAIX"
} vKDRjrF-
Se*GR"Z+
sW#6B+5_k
//打印回应的头信息 5FnWlFc
public void logResponseHead(HttpURLConnection con) z:|4S@9
{ .wx;!9
for(int i=1;;i++) zO2Z\E'%.
{ v?)JM+
String header=con.getHeaderFieldKey(i); nvxftbfE^D
if(header!=null) N9Yc\?_NU_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JMpjiB,A}
Utility.log(header+" : "+con.getHeaderField(header)); +%8c8]2
else $)mE"4FE
break; 8\`]T%h
} 4)-LlYS_d<
} veAGUE %3
5Y"lr Y38
*\I?gDON
public void splitterStop() myFjw@
{ Z= dEk`
bStop = true; ^x4I
} ZyT9y
m ,)4k&d
"kz``6C
} E:(flW=
^:\|6`{n
0eQyzn*98
/* rcPP-+XW
**FileAccess.java W{At3Bfy
*//文件访问(定位，写) [(w_!|S
package NetFox; ^/2n[orl5
import java.io.*; P6zy<w
WL7R.!P
%7Z_Hw
public class FileAccessI implements Serializable{ q*\#HC
Xp{+){Iu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,Zb]3
RandomAccessFile oSavedFile; *;(LKRV
long nPos; B[!wo
ATv.3cy
UW<V(6P
public FileAccessI() throws IOException qXkc~{W_
{ HjbC>*
this("",0); 0~H(GG$VH
} l];,)ddD9
QSW62]=vV
f:GZb?Wyd
public FileAccessI(String sName,long nPos) throws IOException dOqn0Z
{ "Git@%80
oSavedFile = new RandomAccessFile(sName,"rw"); [P]zdw w#
this.nPos = nPos; Lf&p2p?~c
oSavedFile.seek(nPos); tEf_XBjKV
} `B"=\0
+n%uIv
m\__Fl
public synchronized int write(byte[] b,int nStart,int nLen) ZTWbe
{ ;M{ @23?`
int n = -1; :kfHILi
try{ gXZ.je)NM
oSavedFile.write(b,nStart,nLen); d%\{,
n = nLen; wLPL9
} [iwn"e
catch(IOException e) [bIdhG
{ M])Y|}wv8
e.printStackTrace (); ((\s4-
} 81fpeoNO
G%
suN{)"
return n; =LL5E}xP
} B t-o:)pa
AKC';J
j8$*$|
} nKp='>Th
Vz!W(+
(YF`#v6
/* 'xm_oGWE
**SiteInfoBean.java fmXA;^%
*/ &/d;4Eu
package NetFox; XL>cTM
'^'vafs-/@
".O+";wk
public class SiteInfoBean { Lo\+T+n
^rMkCA@;TZ
a?.hvI
private String sSiteURL; //Site's URL \C5YVl#
private String sFilePath; //Saved File's Path k)UF.=$d
private String sFileName; //Saved File's Name f ."bq43(
private int nSplitter; //Count of Splited Downloading File ~C6d5\
?1K|.lr
`/#f8R1g
public SiteInfoBean() G4vXPx%a8
{//nSplitter的缺省值为5 A,{X<mLFb
//default value of nSplitter is 5 <f&z~y=
this("","","",5); Dj'aWyW'
} X(U CN0#
?~$0;5)QC
/L'r L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TYGUB%A
{ 0'wB':v
sSiteURL= sURL; qvy~b
sFilePath = sPath; _nOJ.G
sFileName = sName; (ec?_N0=
this.nSplitter = nSpiltter; Xi^3o
7"Sw))H|
<UOx>=h
} uIvy1h9m
0tv"tA;
ce{(5IC
public String getSSiteURL() 6e3s |
{ >KmOTM<{
return sSiteURL; Lg0Vn&k
} tT'*Uu5
K9B_o,
?2zVWZ
public void setSSiteURL(String value) \ce (/I
{ D]S@U>]M!
sSiteURL = value; _]a8lr+_-
} 3JVENn9
T&c0j(
Veo:G{
public String getSFilePath() (xf_
{ 5@ecZ2`)+h
return sFilePath; mD{<Lp=
} DvCs 5
#5-5N5-1
-B-?z?+(O
public void setSFilePath(String value) YjN2 ,Xi
{ ! /;@kXN
sFilePath = value; Fk@A;22N
} bmgK6OyVR
pXf!8X&y
x%ju(B>
public String getSFileName() =QFnab?N
{ R("g ]
return sFileName; \>0%E{CR
} 99w;Q 2k
QlmZBqK}&
,ef"S r
public void setSFileName(String value) }'mVD^<+
{ WJbdsPs
sFileName = value; ?K%&N99c!
} /fC@T
=+9.X8SP
KKP}fN
public int getNSplitter() f_a.BTtNO
{ Pj9n`LwM
return nSplitter; <3C~<
} )nmLgsg
]L#6'|W
7?a@i;E<
public void setNSplitter(int nCount) T\ZWKx*#
{ D%GB2-j R
nSplitter = nCount; 3mKmd iD
} qD=o;:~Km
} NfvvwG;M
=67dpQ'y
|g<1n
/* }#}IR5`=E
**Utility.java |M]#D0v
*/ b*Ny
package NetFox; 5ws|4V
l^aG"")TH.
`X[L62D
public class Utility { m8'B7|s
I{Hl2?CnI,
y3l3XLI*b
public Utility() eFDhJ
{ ?O(KmDH
4|*b{Ni
t I}@1
} ?w6zq|
w@RVg*`%7D
//线程睡眠 kx,9n)
public static void sleep(int nSecond) VeK^hz R^Z
{ GyI(1OAW
try{ 6(Za}H
Thread.sleep(nSecond); <YX)am'\y
} B;xw @:H
catch(Exception e) <tkxE!xF`J
{ AffVah2o:
e.printStackTrace (); tdZ,sHY6
} *lHI\5
} @i'24Q[6
#;FHyKx
//日志 F7$x5h@
public static void log(String sMsg) cpz'upVOZ
{ :Awnj!KNCc
System.err.println(sMsg); Vj?{T(K1[
} M`IiK+IoU
Trd/\tX#v&
ngF5ywIG
public static void log(int sMsg) sute%6yM
{ O%?TxzX;
System.err.println(sMsg); .Rt_j
} Kq!E<|yM
} vlYDhjZk#
<SM{yMz
6J. [9#
/* YT!QY@qw
**TestMethod.java SN2X{Q|*
*/ S~jl%]
package NetFox; ga0>J_
7^$PauAv
XrR@cDNx{
public class TestMethod { ;#c|ZnX
oFt]q =EU
|jB]5ciT
public TestMethod() 5Pmmt&#/Z
{ ///xx/weblogic60b2_win.exe `L<f15][
try{ L~e\uP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2q}M1-^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bz!9\D|h
SiteFileFetch fileFetch = new SiteFileFetch(bean); hKq <e%oVH
fileFetch.start(); W\09hZ6
} r~q*E'n
catch(Exception e){e.printStackTrace ();} s+Qm/ h2
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}`k >6B
} J }izTI
jU')8m[
Dw}8ci'
public static void main(String[] args) :$Lu V5
{ _r!''@B
new TestMethod(); M7Ej#Y
} ]{0R0Gr94
} 0Yz &aH
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