http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); ,qwuLBW
} MN>b7O \.?
for(int i=0;i<nEndPos.length-1;i++) 9=tIz
{ d-ko ^Y0
nEndPos = nStartPos[i+1]; G*MUO#_iuh
} 7A7?GDW
nEndPos[nEndPos.length-1] = nFileLength; 8Fh)eha9f
} >'$Mp<
} Y@iS_lR
&-w Cvp7
tOD6&<
//启动子线程 3}1u\(Mf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (9d&
for(int i=0;i<nStartPos.length;i++) %;'s4ly
{ .{^5X)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9*wK@yEl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9FR5Jw>t
nStartPos,nEndPos,i); t@;p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wlvgg
fileSplitterFetch.start(); @HCVmg:
} ajT*/L!0_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .P]+? %&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @mBQ?;qlK
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y=KTeYW`
nEndPos = " + nFileLength); D_7,m%Z:
// fileSplitterFetch[nPos.length-1].start(); T-L||yE,h
vr l-$ii
u=sp`%?
//等待子线程结束 Or+U@vAnk
//int count = 0; _[3D
//是否结束while循环 +sA2WK]
boolean breakWhile = false; $%Kfq[Q
BO&bmfp7,
3hH<T.@)
while(!bStop) =nS3p6>rZ
{ C!!M%P
write_nPos(); 6 "sSoj
Utility.sleep(500); B9 uoVcW
breakWhile = true; yyJf%{
!.gIHY
ITBE|b
for(int i=0;i<nStartPos.length;i++) p l0\2e)
{ 3$R1ipb
if(!fileSplitterFetch.bDownOver) +'a^f5
{ !pW0qX\1n
breakWhile = false; d0ksG$
break; /~?*=}c^m
} ND;#7/$>
} %> eiAB_b
if(breakWhile) p2](_}PK
break; Kc-W&?~y#1
fr3d
[q-h|m
//count++; eym4=k ~
//if(count>4) "8MF_Gu):
// siteStop(); 7$=InK
} vE?G7%,
>bW#Zs,6
VONDc1%ga
System.err.println("文件下载结束！"); eauF~md,
} 0h_|t-9j
catch(Exception e){e.printStackTrace ();} T8g$uFo
} %u'ukcL7
6&x@.1('z
7:1Lol-V
//获得文件长度 ZE}}W_
public long getFileSize() :I#V.
{ &QgR*,5eo
int nFileLength = -1; SJ,v?=S!
try{ } Kgy
URL url = new URL(siteInfoBean.getSSiteURL()); :o3N;*o>)0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T~e.PP
httpConnection.setRequestProperty("User-Agent","NetFox"); ,J@
S1_RjMbYM
#6=
int responseCode=httpConnection.getResponseCode(); {wKB;?fUvk
if(responseCode>=400) {<KVx9
{ ?caSb=f
processErrorCode(responseCode); [W&T(%(W-
return -2; //-2 represent access is error S9.o/mr
} 4pvMd
@ 6vIap|
W<g1<z\f
String sHeader; xJe%f\UDu
n[rCQdM&U"
$UwCMPs X
for(int i=1;;i++) ]f_p8?j"
{ 9.#<b|g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mfr|:i
//Utility.log(in.readLine()); z{QqY.Gu{G
sHeader=httpConnection.getHeaderFieldKey(i); ~"!fP3"e
if(sHeader!=null) B@ EC5Ap*
{ N!}f}oF
if(sHeader.equals("Content-Length")) %N._w!N<5n
{ ]-#DB^EQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uY To9A
break; W>r+h-kR
} h*\%vr
} Le^ n +5x
else ih3n<gXF
break; SXh-A1t
} XiWmV ?
} K&-"d/QuLg
catch(IOException e){e.printStackTrace ();} !N^@4*
catch(Exception e){e.printStackTrace ();} {.Jlbi9!
xmoxZW:
:3 mh@[V
Utility.log(nFileLength); +}AI@+
@6.vKCSE
]SEZaT
return nFileLength; sI2^Qp@O1
} h(DTa
QT}tvm@PMq
<P<z N~i9j
//保存下载信息（文件指针位置） Mtx4'WZ
private void write_nPos() ~W/z96' 5
{ V7/Rby Q
try{ [}m[)L\
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8ao_i=&x
output.writeInt(nStartPos.length); UiNP3TJ'L
for(int i=0;i<nStartPos.length;i++) V;=cwy)I
{ ;tf=gdX;
// output.writeLong(nPos); DY*N|OnqJ
output.writeLong(fileSplitterFetch.nStartPos); EU#^7
output.writeLong(fileSplitterFetch.nEndPos); |7~<Is~*
} >$7B wO
output.close(); 6S#Cl>v
} Z\sDUJ
catch(IOException e){e.printStackTrace ();} Lw,h+@0
catch(Exception e){e.printStackTrace ();} "dlVk~
} /-s6<e!
;Rf'P}"]
zQ PQ
//读取保存的下载信息（文件指针位置） E{(;@PzE
private void read_nPos() fP1!)po
{ e3\T)x&=
try{ !,PWb3S
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Gc7=
int nCount = input.readInt(); '3;b@g,
nStartPos = new long[nCount]; RnN!2K
nEndPos = new long[nCount]; W,u:gzmhw
for(int i=0;i<nStartPos.length;i++) ;.C\Ss<>*
{ k?}Zg*
nStartPos = input.readLong(); '+ ?X
nEndPos = input.readLong(); V]^$S"Tv
} X8\GzNE~R
input.close(); HaYo!.(Fv
} ;*J
catch(IOException e){e.printStackTrace ();} xSu >
catch(Exception e){e.printStackTrace ();} B5QFK
} 5V-I1B&
wIgS3K
Bw.i}3UT6
private void processErrorCode(int nErrorCode) Bw yx c
{ -\MG}5?!
System.err.println("Error Code : " + nErrorCode); FI.\%x
} d(K+);!
I^]nqK
Vvo7C!$z
//停止文件下载 6u%&<")4HP
public void siteStop() dN6?c'iN?2
{ 7p[n
bStop = true; qP ,EBE
for(int i=0;i<nStartPos.length;i++) '"Nr,vQo
fileSplitterFetch.splitterStop(); X3& Jb2c2
1~gCtBRM
PY'2h4IL
} y7<|_:00
} CJyevMf'
//负责部分文件的抓取 Y-9I3?ar
**FileSplitterFetch.java &5;"#:ORcK
*/ l-3~K-k<@
package NetFox; 18Emi<&A
Ort(AfW
p<%d2@lp
import java.io.*; 76SXJ9@x
import java.net.*; !IR6 ,A\
@VI@fN
@6]JIJE
public class FileSplitterFetch extends Thread { {..6>fS
Ul# r
N>E_%]Ch
String sURL; //File URL D+c>F5
long nStartPos; //File Snippet Start Position IGgL7^MF
long nEndPos; //File Snippet End Position ,: ^u-b|
int nThreadID; //Thread's ID ~"bVL[
boolean bDownOver = false; //Downing is over *^r}"in
boolean bStop = false; //Stop identical iDD$pd,e\
FileAccessI fileAccessI = null; //File Access interface fV~~J2IK
_v:SP LU
#K&Gp-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +,l-Nz
{ 3U}%2ARo_
this.sURL = sURL; HKeK<V
this.nStartPos = nStart; BLFdHB.$T
this.nEndPos = nEnd; Lj7AZ|k
nThreadID = id; ^^Vg~){4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d_CT$
} VaPG-n>Vf
eH,or,r
{)Xy%QV
public void run() j1Ezf=N6`
{ 4z)]@:`}z
while(nStartPos < nEndPos && !bStop) ?4uL-z](V
{ )gi9f1n`
d5-qZ{W
r<\u6jF
try{ ,z6~?6m
URL url = new URL(sURL); 0`H# '/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qSQ~D(tO
httpConnection.setRequestProperty("User-Agent","NetFox"); 1*7@BP5
String sProperty = "bytes="+nStartPos+"-"; Zd&S@Z
httpConnection.setRequestProperty("RANGE",sProperty); ('~LMu_
Utility.log(sProperty); &Qm@9Is
V6Dbd" i9
,,TnIouy
InputStream input = httpConnection.getInputStream(); $Q0n
//logResponseHead(httpConnection); W3RT{\
]'S^]
6B-16
byte[] b = new byte[1024]; Wl4%GB
int nRead; =V5%+/r+f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5-M-X#(
{ AwN!;t_0+N
nStartPos += fileAccessI.write(b,0,nRead); ^@]3R QB
//if(nThreadID == 1) `mqMLo*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \NC3'G:Ii
} Mihg:
>3bCTE
,?3G;-
Utility.log("Thread " + nThreadID + " is over!"); z{>Rc"%\
bDownOver = true; GthYzd:'hJ
//nPos = fileAccessI.write (b,0,nRead); Ho%CDz z
} Gh$^{
catch(Exception e){e.printStackTrace ();} Zc2PepIg
} v0y(58Rz.
} 0IpmRH/
r*Xuj=
;d?R:Uw8
//打印回应的头信息 F[0]/
public void logResponseHead(HttpURLConnection con) ~K=b\xc^
{ Mp]rUPK
for(int i=1;;i++) pJ{Y lS{
{ W>LR\]Ti@
String header=con.getHeaderFieldKey(i); ?#fQ~ s
if(header!=null) .^g p?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'PHl$f*k
Utility.log(header+" : "+con.getHeaderField(header)); +h$ 9\
else cnLro
break; 4I7>f]=)
} #/]nxW.S
} ;Xw~D_uv
d'2A,B~_*
HTtnXBJ)*H
public void splitterStop() saAF+H/=
{ YS ][n_
bStop = true; qWw=8Bq
} o(HbGHIP
j<x_&1
W%J\qA
} (#'>(t(4
NO3/rJ6-
j#6.Gq
/* qb4z T
**FileAccess.java e;jdqF~v!
*//文件访问(定位，写) o}!PQ#`M
package NetFox; ME dWLFf
import java.io.*; UI#h&j5pW
ww/Uzv
*](iS
public class FileAccessI implements Serializable{ ix$bRdl
_j3fAr(V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M`>E|"<
RandomAccessFile oSavedFile; 1"g<0 W
long nPos; >V~E]P%@
Lv%x81]K
]{iQ21`a-
public FileAccessI() throws IOException $C\BcKlmv
{ :%.D78&
this("",0); #`IN`m|
} MJvp6n
Vc2`b3"Br
g'gdgfvn
public FileAccessI(String sName,long nPos) throws IOException #S(Hd?34,
{ v1[29t<I!
oSavedFile = new RandomAccessFile(sName,"rw"); XRH!]!
this.nPos = nPos; Uv.)?YeGh
oSavedFile.seek(nPos); wbHb;]
} TNth
+0~YP*I`/
grYe&(`X
public synchronized int write(byte[] b,int nStart,int nLen) G?ZXWu.
{ weQ_*<5%
int n = -1; 8RX&k
try{ uS-|wYE
oSavedFile.write(b,nStart,nLen); 2?5>o!C
n = nLen; q@qsp&0/
} /ouPg=+Nl
catch(IOException e) e!Hhs/&!T
{ _^;Z~/.
e.printStackTrace (); : 'c&,oLY
} xmG<]WF>E
G#CXs:1pd+
liZxBs :%i
return n; ?0SEMmp`H
} *Uh!>Iv;
RpK@?[4s
g*Phv|kI
} '7/)Ot(
+:f"Y0
hc1N~$3!G
/* `gJ(0#ac
**SiteInfoBean.java Gq6*SaTk
*/ TJN4k@\$2
package NetFox; y*? Jui Q
nEfK53i_
<[v[ci
public class SiteInfoBean { %RVZD#zr
IcEdG(
)7d&NE_
private String sSiteURL; //Site's URL \lY_~*J
private String sFilePath; //Saved File's Path 4JEpl'5^Q
private String sFileName; //Saved File's Name TV:9bn?r)
private int nSplitter; //Count of Splited Downloading File .N3mb6#[R
SKtrtm
-} +[
public SiteInfoBean() S3#>9k;p
{//nSplitter的缺省值为5 So;<6~
//default value of nSplitter is 5 .6> w'F{>
this("","","",5); R/_&m$ZB
} %C0Dw\A*:
B[}6-2<>?C
H.;Q+A,8^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B1gR5p0
{ E@\e$?*X
sSiteURL= sURL; LscGTs,
sFilePath = sPath; GB^Br6
sFileName = sName; 7nSxi+6e
this.nSplitter = nSpiltter; fOHxtHM
5N]"~w*
jylD6IT
} [?gP;,
B:<VA=
5^cCY'I
public String getSSiteURL() 5xBbrU;
{ =%7-ZH9
return sSiteURL; /xQTxh1;K
} NRuNKl.v
TrNF=x>
0"R|..l/
public void setSSiteURL(String value) ~~.}ah/_d
{ ta0|^KAA
sSiteURL = value; xG 1nGO
} [WJ+h~~ o
Ni>[D"|
Smh,zCc>s
public String getSFilePath() vI?, 47Hj+
{ 7^Uv7<pw
return sFilePath; SJLis"8
} 7=uj2.J6
JT?h1v<H]
WAqINLdX
public void setSFilePath(String value) _g8yDfcLG
{ ^Pf WG*
sFilePath = value; y7{?Ip4[
} AX INThJ
]|@^1we
JJnH%Q
public String getSFileName() <q836]aaA
{ \wZe] G%S
return sFileName; bD^owa
} T|$H#n}
*a)n62
mv><HqDL1
public void setSFileName(String value) TC('H[ ]
{ #mT"gs
sFileName = value; `^vE9nW7
} -LSWmrj
LeQjvW9y
"Q<MS'a
public int getNSplitter() VTM/hJmwJ
{ wzA$'+Mb
return nSplitter; =|=(l)8
} }bDm@NU
bcyzhK=
1 zZlC#V
public void setNSplitter(int nCount) ]5O~+Nf
{ =]t|];c%
nSplitter = nCount; 0b>h$OU/
} 7$b1<.WX
} _!6jR5&r,
f3;5Am
h8P)%p
/* M}a6Vu9
**Utility.java 3]>| i
*/ 0sqFF[i
package NetFox; >z03{=sAN
\bF{-"7.
H|*m$|$,
public class Utility { [ 3Gf2_
8}[).d160
XX@ZQcN
public Utility() T%Lx%Qn
{ .>S!ji
Ba,`TJ%y
eRYK3W
} \RiP
yfSmDPh
//线程睡眠 hM{bavd
public static void sleep(int nSecond) NUZl`fu1Z4
{ 8y L Y
try{ zda 3 ,U2o
Thread.sleep(nSecond); UZMd~|
} uT{q9=w
catch(Exception e) uD'6mk*
{ &&+H+{_Q
e.printStackTrace (); ]'}L 1r
} )UR7i8]!0
} VRMXtQ*1Dm
E.TAbD&5(
//日志 pb}*\/s
public static void log(String sMsg) &HW9Jn
{ O?2DQY?jT
System.err.println(sMsg); +nL[MSw
} ![1rzQvGDb
-~1~I e2
TxD#9]Q`
public static void log(int sMsg) 2 nCA<&
{ $]d^-{|
System.err.println(sMsg); E fDH6
} 6N4~~O
} \85i+q:LuA
gJXaPJA{
N['.BN
/* 0;k# *#w
**TestMethod.java 3n _htgcv
*/ siI;"?
package NetFox; Upe%rC(
u_enqC3
? t|[?
public class TestMethod { QV!up^Zso
2ESo2
]DcFySyv
public TestMethod() HtFDlvdy]
{ ///xx/weblogic60b2_win.exe $Yq9P0Ya
try{ zfU{Kd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U/U);frH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &8H'eAA
SiteFileFetch fileFetch = new SiteFileFetch(bean); b=vkiO`2
fileFetch.start(); t_^4`dW`
} Y7|EIAU5Y
catch(Exception e){e.printStackTrace ();} w{KavU5W
Hka2
L,\Iasv
} aUp g u"
KoT\pY^7\
g#bRT*,L
public static void main(String[] args) ^W^OfY
{ @dKTx#gZ
new TestMethod(); s<Ziegmw|g
} +>,I1{u%&
} m`XHKRp
点击下载更多相关资料